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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2003 Intel Corp.
6 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05007 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
9 * These functions implement the sctp_outq class. The outqueue handles
10 * bundling and queueing of outgoing SCTP chunks.
11 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050012 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050018 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Perry Melange <pmelange@null.cc.uic.edu>
40 * Xingang Guo <xingang.guo@intel.com>
41 * Hui Huang <hui.huang@nokia.com>
42 * Sridhar Samudrala <sri@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 *
45 * Any bugs reported given to us we will try to fix... any fixes shared will
46 * be incorporated into the next SCTP release.
47 */
48
Joe Perches145ce502010-08-24 13:21:08 +000049#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <linux/types.h>
52#include <linux/list.h> /* For struct list_head */
53#include <linux/socket.h>
54#include <linux/ip.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090055#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#include <net/sock.h> /* For skb_set_owner_w */
57
58#include <net/sctp/sctp.h>
59#include <net/sctp/sm.h>
60
61/* Declare internal functions here. */
62static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
63static void sctp_check_transmitted(struct sctp_outq *q,
64 struct list_head *transmitted_queue,
65 struct sctp_transport *transport,
66 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -040067 __u32 *highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69static void sctp_mark_missing(struct sctp_outq *q,
70 struct list_head *transmitted_queue,
71 struct sctp_transport *transport,
72 __u32 highest_new_tsn,
73 int count_of_newacks);
74
75static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
76
Adrian Bunkabd0b1982008-07-22 14:20:45 -070077static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout);
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079/* Add data to the front of the queue. */
80static inline void sctp_outq_head_data(struct sctp_outq *q,
81 struct sctp_chunk *ch)
82{
David S. Miller79af02c2005-07-08 21:47:49 -070083 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085}
86
87/* Take data from the front of the queue. */
88static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
89{
David S. Miller79af02c2005-07-08 21:47:49 -070090 struct sctp_chunk *ch = NULL;
91
92 if (!list_empty(&q->out_chunk_list)) {
93 struct list_head *entry = q->out_chunk_list.next;
94
95 ch = list_entry(entry, struct sctp_chunk, list);
96 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 q->out_qlen -= ch->skb->len;
David S. Miller79af02c2005-07-08 21:47:49 -070098 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 return ch;
100}
101/* Add data chunk to the end of the queue. */
102static inline void sctp_outq_tail_data(struct sctp_outq *q,
103 struct sctp_chunk *ch)
104{
David S. Miller79af02c2005-07-08 21:47:49 -0700105 list_add_tail(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107}
108
109/*
110 * SFR-CACC algorithm:
111 * D) If count_of_newacks is greater than or equal to 2
112 * and t was not sent to the current primary then the
113 * sender MUST NOT increment missing report count for t.
114 */
115static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
116 struct sctp_transport *transport,
117 int count_of_newacks)
118{
119 if (count_of_newacks >=2 && transport != primary)
120 return 1;
121 return 0;
122}
123
124/*
125 * SFR-CACC algorithm:
126 * F) If count_of_newacks is less than 2, let d be the
127 * destination to which t was sent. If cacc_saw_newack
128 * is 0 for destination d, then the sender MUST NOT
129 * increment missing report count for t.
130 */
131static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
132 int count_of_newacks)
133{
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000134 if (count_of_newacks < 2 &&
135 (transport && !transport->cacc.cacc_saw_newack))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 return 1;
137 return 0;
138}
139
140/*
141 * SFR-CACC algorithm:
142 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
143 * execute steps C, D, F.
144 *
145 * C has been implemented in sctp_outq_sack
146 */
147static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
148 struct sctp_transport *transport,
149 int count_of_newacks)
150{
151 if (!primary->cacc.cycling_changeover) {
152 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
153 return 1;
154 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
155 return 1;
156 return 0;
157 }
158 return 0;
159}
160
161/*
162 * SFR-CACC algorithm:
163 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
164 * than next_tsn_at_change of the current primary, then
165 * the sender MUST NOT increment missing report count
166 * for t.
167 */
168static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
169{
170 if (primary->cacc.cycling_changeover &&
171 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
172 return 1;
173 return 0;
174}
175
176/*
177 * SFR-CACC algorithm:
178 * 3) If the missing report count for TSN t is to be
179 * incremented according to [RFC2960] and
180 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300181 * then the sender MUST further execute steps 3.1 and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 * 3.2 to determine if the missing report count for
183 * TSN t SHOULD NOT be incremented.
184 *
185 * 3.3) If 3.1 and 3.2 do not dictate that the missing
186 * report count for t should not be incremented, then
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300187 * the sender SHOULD increment missing report count for
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
189 */
190static inline int sctp_cacc_skip(struct sctp_transport *primary,
191 struct sctp_transport *transport,
192 int count_of_newacks,
193 __u32 tsn)
194{
195 if (primary->cacc.changeover_active &&
Joe Perchesf64f9e72009-11-29 16:55:45 -0800196 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) ||
197 sctp_cacc_skip_3_2(primary, tsn)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 return 1;
199 return 0;
200}
201
202/* Initialize an existing sctp_outq. This does the boring stuff.
203 * You still need to define handlers if you really want to DO
204 * something with this structure...
205 */
206void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
207{
208 q->asoc = asoc;
David S. Miller79af02c2005-07-08 21:47:49 -0700209 INIT_LIST_HEAD(&q->out_chunk_list);
210 INIT_LIST_HEAD(&q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 INIT_LIST_HEAD(&q->retransmit);
212 INIT_LIST_HEAD(&q->sacked);
213 INIT_LIST_HEAD(&q->abandoned);
214
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700215 q->fast_rtx = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 q->outstanding_bytes = 0;
217 q->empty = 1;
218 q->cork = 0;
219
220 q->malloced = 0;
221 q->out_qlen = 0;
222}
223
224/* Free the outqueue structure and any related pending chunks.
225 */
226void sctp_outq_teardown(struct sctp_outq *q)
227{
228 struct sctp_transport *transport;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700229 struct list_head *lchunk, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700230 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
232 /* Throw away unacknowledged chunks. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700233 list_for_each_entry(transport, &q->asoc->peer.transport_addr_list,
234 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
236 chunk = list_entry(lchunk, struct sctp_chunk,
237 transmitted_list);
238 /* Mark as part of a failed message. */
239 sctp_chunk_fail(chunk, q->error);
240 sctp_chunk_free(chunk);
241 }
242 }
243
244 /* Throw away chunks that have been gap ACKed. */
245 list_for_each_safe(lchunk, temp, &q->sacked) {
246 list_del_init(lchunk);
247 chunk = list_entry(lchunk, struct sctp_chunk,
248 transmitted_list);
249 sctp_chunk_fail(chunk, q->error);
250 sctp_chunk_free(chunk);
251 }
252
253 /* Throw away any chunks in the retransmit queue. */
254 list_for_each_safe(lchunk, temp, &q->retransmit) {
255 list_del_init(lchunk);
256 chunk = list_entry(lchunk, struct sctp_chunk,
257 transmitted_list);
258 sctp_chunk_fail(chunk, q->error);
259 sctp_chunk_free(chunk);
260 }
261
262 /* Throw away any chunks that are in the abandoned queue. */
263 list_for_each_safe(lchunk, temp, &q->abandoned) {
264 list_del_init(lchunk);
265 chunk = list_entry(lchunk, struct sctp_chunk,
266 transmitted_list);
267 sctp_chunk_fail(chunk, q->error);
268 sctp_chunk_free(chunk);
269 }
270
271 /* Throw away any leftover data chunks. */
272 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
273
274 /* Mark as send failure. */
275 sctp_chunk_fail(chunk, q->error);
276 sctp_chunk_free(chunk);
277 }
278
279 q->error = 0;
280
281 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700282 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
283 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700285 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}
287
288/* Free the outqueue structure and any related pending chunks. */
289void sctp_outq_free(struct sctp_outq *q)
290{
291 /* Throw away leftover chunks. */
292 sctp_outq_teardown(q);
293
294 /* If we were kmalloc()'d, free the memory. */
295 if (q->malloced)
296 kfree(q);
297}
298
299/* Put a new chunk in an sctp_outq. */
300int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
301{
302 int error = 0;
303
304 SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
305 q, chunk, chunk && chunk->chunk_hdr ?
306 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
307 : "Illegal Chunk");
308
309 /* If it is data, queue it up, otherwise, send it
310 * immediately.
311 */
Shan Weiec7b9512010-04-30 22:41:09 -0400312 if (sctp_chunk_is_data(chunk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 /* Is it OK to queue data chunks? */
314 /* From 9. Termination of Association
315 *
316 * When either endpoint performs a shutdown, the
317 * association on each peer will stop accepting new
318 * data from its user and only deliver data in queue
319 * at the time of sending or receiving the SHUTDOWN
320 * chunk.
321 */
322 switch (q->asoc->state) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 case SCTP_STATE_CLOSED:
324 case SCTP_STATE_SHUTDOWN_PENDING:
325 case SCTP_STATE_SHUTDOWN_SENT:
326 case SCTP_STATE_SHUTDOWN_RECEIVED:
327 case SCTP_STATE_SHUTDOWN_ACK_SENT:
328 /* Cannot send after transport endpoint shutdown */
329 error = -ESHUTDOWN;
330 break;
331
332 default:
333 SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
334 q, chunk, chunk && chunk->chunk_hdr ?
335 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
336 : "Illegal Chunk");
337
338 sctp_outq_tail_data(q, chunk);
339 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
340 SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
341 else
342 SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
343 q->empty = 0;
344 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700345 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700347 list_add_tail(&chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
349 }
350
351 if (error < 0)
352 return error;
353
354 if (!q->cork)
355 error = sctp_outq_flush(q, 0);
356
357 return error;
358}
359
360/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
361 * and the abandoned list are in ascending order.
362 */
363static void sctp_insert_list(struct list_head *head, struct list_head *new)
364{
365 struct list_head *pos;
366 struct sctp_chunk *nchunk, *lchunk;
367 __u32 ntsn, ltsn;
368 int done = 0;
369
370 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
371 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
372
373 list_for_each(pos, head) {
374 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
375 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
376 if (TSN_lt(ntsn, ltsn)) {
377 list_add(new, pos->prev);
378 done = 1;
379 break;
380 }
381 }
382 if (!done)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900383 list_add_tail(new, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384}
385
386/* Mark all the eligible packets on a transport for retransmission. */
387void sctp_retransmit_mark(struct sctp_outq *q,
388 struct sctp_transport *transport,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400389 __u8 reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390{
391 struct list_head *lchunk, *ltemp;
392 struct sctp_chunk *chunk;
393
394 /* Walk through the specified transmitted queue. */
395 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
396 chunk = list_entry(lchunk, struct sctp_chunk,
397 transmitted_list);
398
399 /* If the chunk is abandoned, move it to abandoned list. */
400 if (sctp_chunk_abandoned(chunk)) {
401 list_del_init(lchunk);
402 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800403
404 /* If this chunk has not been previousely acked,
405 * stop considering it 'outstanding'. Our peer
406 * will most likely never see it since it will
407 * not be retransmitted
408 */
409 if (!chunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400410 if (chunk->transport)
411 chunk->transport->flight_size -=
412 sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800413 q->outstanding_bytes -= sctp_data_size(chunk);
414 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
415 sizeof(struct sk_buff));
416 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 continue;
418 }
419
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400420 /* If we are doing retransmission due to a timeout or pmtu
421 * discovery, only the chunks that are not yet acked should
422 * be added to the retransmit queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400424 if ((reason == SCTP_RTXR_FAST_RTX &&
Neil Hormanc226ef92008-07-25 12:44:09 -0400425 (chunk->fast_retransmit == SCTP_NEED_FRTX)) ||
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400426 (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 /* RFC 2960 6.2.1 Processing a Received SACK
428 *
429 * C) Any time a DATA chunk is marked for
430 * retransmission (via either T3-rtx timer expiration
431 * (Section 6.3.3) or via fast retransmit
432 * (Section 7.2.4)), add the data size of those
433 * chunks to the rwnd.
434 */
Sridhar Samudralacd497882006-09-29 17:09:05 -0700435 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
436 sizeof(struct sk_buff));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 q->outstanding_bytes -= sctp_data_size(chunk);
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400438 if (chunk->transport)
439 transport->flight_size -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
441 /* sctpimpguide-05 Section 2.8.2
442 * M5) If a T3-rtx timer expires, the
443 * 'TSN.Missing.Report' of all affected TSNs is set
444 * to 0.
445 */
446 chunk->tsn_missing_report = 0;
447
448 /* If a chunk that is being used for RTT measurement
449 * has to be retransmitted, we cannot use this chunk
450 * anymore for RTT measurements. Reset rto_pending so
451 * that a new RTT measurement is started when a new
452 * data chunk is sent.
453 */
454 if (chunk->rtt_in_progress) {
455 chunk->rtt_in_progress = 0;
456 transport->rto_pending = 0;
457 }
458
459 /* Move the chunk to the retransmit queue. The chunks
460 * on the retransmit queue are always kept in order.
461 */
462 list_del_init(lchunk);
463 sctp_insert_list(&q->retransmit, lchunk);
464 }
465 }
466
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400467 SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 "cwnd: %d, ssthresh: %d, flight_size: %d, "
Harvey Harrison0dc47872008-03-05 20:47:47 -0800469 "pba: %d\n", __func__,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400470 transport, reason,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 transport->cwnd, transport->ssthresh,
472 transport->flight_size,
473 transport->partial_bytes_acked);
474
475}
476
477/* Mark all the eligible packets on a transport for retransmission and force
478 * one packet out.
479 */
480void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
481 sctp_retransmit_reason_t reason)
482{
483 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
485 switch(reason) {
486 case SCTP_RTXR_T3_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700487 SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
489 /* Update the retran path if the T3-rtx timer has expired for
490 * the current retran path.
491 */
492 if (transport == transport->asoc->peer.retran_path)
493 sctp_assoc_update_retran_path(transport->asoc);
Neil Horman58fbbed2008-02-29 11:40:56 -0800494 transport->asoc->rtx_data_chunks +=
495 transport->asoc->unack_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 break;
497 case SCTP_RTXR_FAST_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700498 SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700500 q->fast_rtx = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 break;
502 case SCTP_RTXR_PMTUD:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700503 SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 break;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400505 case SCTP_RTXR_T1_RTX:
506 SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS);
Neil Horman58fbbed2008-02-29 11:40:56 -0800507 transport->asoc->init_retries++;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400508 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700509 default:
510 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 }
512
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400513 sctp_retransmit_mark(q, transport, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
515 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
516 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
517 * following the procedures outlined in C1 - C5.
518 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700519 if (reason == SCTP_RTXR_T3_RTX)
520 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700522 /* Flush the queues only on timeout, since fast_rtx is only
523 * triggered during sack processing and the queue
524 * will be flushed at the end.
525 */
526 if (reason != SCTP_RTXR_FAST_RTX)
527 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
529 if (error)
530 q->asoc->base.sk->sk_err = -error;
531}
532
533/*
534 * Transmit DATA chunks on the retransmit queue. Upon return from
535 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
536 * need to be transmitted by the caller.
537 * We assume that pkt->transport has already been set.
538 *
539 * The return value is a normal kernel error return value.
540 */
541static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
542 int rtx_timeout, int *start_timer)
543{
544 struct list_head *lqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 struct sctp_transport *transport = pkt->transport;
546 sctp_xmit_t status;
547 struct sctp_chunk *chunk, *chunk1;
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 lqueue = &q->retransmit;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700554 fast_rtx = q->fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700556 /* This loop handles time-out retransmissions, fast retransmissions,
557 * and retransmissions due to opening of whindow.
558 *
559 * RFC 2960 6.3.3 Handle T3-rtx Expiration
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 *
561 * E3) Determine how many of the earliest (i.e., lowest TSN)
562 * outstanding DATA chunks for the address for which the
563 * T3-rtx has expired will fit into a single packet, subject
564 * to the MTU constraint for the path corresponding to the
565 * destination transport address to which the retransmission
566 * is being sent (this may be different from the address for
567 * which the timer expires [see Section 6.4]). Call this value
568 * K. Bundle and retransmit those K DATA chunks in a single
569 * packet to the destination endpoint.
570 *
571 * [Just to be painfully clear, if we are retransmitting
572 * because a timeout just happened, we should send only ONE
573 * packet of retransmitted data.]
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700574 *
575 * For fast retransmissions we also send only ONE packet. However,
576 * if we are just flushing the queue due to open window, we'll
577 * try to send as much as possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700579 list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) {
Wei Yongjun4c6a6f42011-04-19 21:32:28 +0000580 /* If the chunk is abandoned, move it to abandoned list. */
581 if (sctp_chunk_abandoned(chunk)) {
582 list_del_init(&chunk->transmitted_list);
583 sctp_insert_list(&q->abandoned,
584 &chunk->transmitted_list);
585 continue;
586 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588 /* Make sure that Gap Acked TSNs are not retransmitted. A
589 * simple approach is just to move such TSNs out of the
590 * way and into a 'transmitted' queue and skip to the
591 * next chunk.
592 */
593 if (chunk->tsn_gap_acked) {
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700594 list_del(&chunk->transmitted_list);
595 list_add_tail(&chunk->transmitted_list,
596 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 continue;
598 }
599
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700600 /* If we are doing fast retransmit, ignore non-fast_rtransmit
601 * chunks
602 */
603 if (fast_rtx && !chunk->fast_retransmit)
604 continue;
605
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400606redo:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 /* Attempt to append this chunk to the packet. */
608 status = sctp_packet_append_chunk(pkt, chunk);
609
610 switch (status) {
611 case SCTP_XMIT_PMTU_FULL:
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400612 if (!pkt->has_data && !pkt->has_cookie_echo) {
613 /* If this packet did not contain DATA then
614 * retransmission did not happen, so do it
615 * again. We'll ignore the error here since
616 * control chunks are already freed so there
617 * is nothing we can do.
618 */
619 sctp_packet_transmit(pkt);
620 goto redo;
621 }
622
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700624 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
626 /* If we are retransmitting, we should only
627 * send a single packet.
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000628 * Otherwise, try appending this chunk again.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700630 if (rtx_timeout || fast_rtx)
631 done = 1;
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000632 else
633 goto redo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700635 /* Bundle next chunk in the next round. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 break;
637
638 case SCTP_XMIT_RWND_FULL:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900639 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700640 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
642 /* Stop sending DATA as there is no more room
643 * at the receiver.
644 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700645 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 break;
647
648 case SCTP_XMIT_NAGLE_DELAY:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900649 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700650 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651
652 /* Stop sending DATA because of nagle delay. */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700653 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 break;
655
656 default:
657 /* The append was successful, so add this chunk to
658 * the transmitted list.
659 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700660 list_del(&chunk->transmitted_list);
661 list_add_tail(&chunk->transmitted_list,
662 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900664 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 * after it is retransmitted.
666 */
Neil Hormanc226ef92008-07-25 12:44:09 -0400667 if (chunk->fast_retransmit == SCTP_NEED_FRTX)
668 chunk->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 q->empty = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700672 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700674 /* Set the timer if there were no errors */
675 if (!error && !timer)
676 timer = 1;
677
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700678 if (done)
679 break;
680 }
681
682 /* If we are here due to a retransmit timeout or a fast
683 * retransmit and if there are any chunks left in the retransmit
684 * queue that could not fit in the PMTU sized packet, they need
685 * to be marked as ineligible for a subsequent fast retransmit.
686 */
687 if (rtx_timeout || fast_rtx) {
688 list_for_each_entry(chunk1, lqueue, transmitted_list) {
Neil Hormanc226ef92008-07-25 12:44:09 -0400689 if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
690 chunk1->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 }
692 }
693
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700694 *start_timer = timer;
695
696 /* Clear fast retransmit hint */
697 if (fast_rtx)
698 q->fast_rtx = 0;
699
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 return error;
701}
702
703/* Cork the outqueue so queued chunks are really queued. */
704int sctp_outq_uncork(struct sctp_outq *q)
705{
706 int error = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500707 if (q->cork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 q->cork = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500709 error = sctp_outq_flush(q, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 return error;
711}
712
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700713
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714/*
715 * Try to flush an outqueue.
716 *
717 * Description: Send everything in q which we legally can, subject to
718 * congestion limitations.
719 * * Note: This function can be called from multiple contexts so appropriate
720 * locking concerns must be made. Today we use the sock lock to protect
721 * this function.
722 */
Adrian Bunkabd0b1982008-07-22 14:20:45 -0700723static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724{
725 struct sctp_packet *packet;
726 struct sctp_packet singleton;
727 struct sctp_association *asoc = q->asoc;
728 __u16 sport = asoc->base.bind_addr.port;
729 __u16 dport = asoc->peer.port;
730 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 struct sctp_transport *transport = NULL;
732 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700733 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 sctp_xmit_t status;
735 int error = 0;
736 int start_timer = 0;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700737 int one_packet = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
739 /* These transports have chunks to send. */
740 struct list_head transport_list;
741 struct list_head *ltransport;
742
743 INIT_LIST_HEAD(&transport_list);
744 packet = NULL;
745
746 /*
747 * 6.10 Bundling
748 * ...
749 * When bundling control chunks with DATA chunks, an
750 * endpoint MUST place control chunks first in the outbound
751 * SCTP packet. The transmitter MUST transmit DATA chunks
752 * within a SCTP packet in increasing order of TSN.
753 * ...
754 */
755
David S. Miller79af02c2005-07-08 21:47:49 -0700756 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
757 list_del_init(&chunk->list);
758
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 /* Pick the right transport to use. */
760 new_transport = chunk->transport;
761
762 if (!new_transport) {
Vlad Yasevicha08de642007-12-20 14:11:47 -0800763 /*
764 * If we have a prior transport pointer, see if
765 * the destination address of the chunk
766 * matches the destination address of the
767 * current transport. If not a match, then
768 * try to look up the transport with a given
769 * destination address. We do this because
770 * after processing ASCONFs, we may have new
771 * transports created.
772 */
773 if (transport &&
774 sctp_cmp_addr_exact(&chunk->dest,
775 &transport->ipaddr))
776 new_transport = transport;
777 else
778 new_transport = sctp_assoc_lookup_paddr(asoc,
779 &chunk->dest);
780
781 /* if we still don't have a new transport, then
782 * use the current active path.
783 */
784 if (!new_transport)
785 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700786 } else if ((new_transport->state == SCTP_INACTIVE) ||
787 (new_transport->state == SCTP_UNCONFIRMED)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700788 /* If the chunk is Heartbeat or Heartbeat Ack,
789 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 * inactive.
791 *
792 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900793 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 * A HEARTBEAT ACK is always sent to the source IP
795 * address of the IP datagram containing the
796 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900797 * ...
Vlad Yasevicha08de642007-12-20 14:11:47 -0800798 *
799 * ASCONF_ACKs also must be sent to the source.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 */
801 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
Vlad Yasevicha08de642007-12-20 14:11:47 -0800802 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
803 chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 new_transport = asoc->peer.active_path;
805 }
806
807 /* Are we switching transports?
808 * Take care of transport locks.
809 */
810 if (new_transport != transport) {
811 transport = new_transport;
812 if (list_empty(&transport->send_ready)) {
813 list_add_tail(&transport->send_ready,
814 &transport_list);
815 }
816 packet = &transport->packet;
817 sctp_packet_config(packet, vtag,
818 asoc->peer.ecn_capable);
819 }
820
821 switch (chunk->chunk_hdr->type) {
822 /*
823 * 6.10 Bundling
824 * ...
825 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
826 * COMPLETE with any other chunks. [Send them immediately.]
827 */
828 case SCTP_CID_INIT:
829 case SCTP_CID_INIT_ACK:
830 case SCTP_CID_SHUTDOWN_COMPLETE:
831 sctp_packet_init(&singleton, transport, sport, dport);
832 sctp_packet_config(&singleton, vtag, 0);
833 sctp_packet_append_chunk(&singleton, chunk);
834 error = sctp_packet_transmit(&singleton);
835 if (error < 0)
836 return error;
837 break;
838
839 case SCTP_CID_ABORT:
Gui Jianfengf4ad85c2008-04-12 18:39:34 -0700840 if (sctp_test_T_bit(chunk)) {
841 packet->vtag = asoc->c.my_vtag;
842 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700843 /* The following chunks are "response" chunks, i.e.
844 * they are generated in response to something we
845 * received. If we are sending these, then we can
846 * send only 1 packet containing these chunks.
847 */
848 case SCTP_CID_HEARTBEAT_ACK:
849 case SCTP_CID_SHUTDOWN_ACK:
850 case SCTP_CID_COOKIE_ACK:
851 case SCTP_CID_COOKIE_ECHO:
852 case SCTP_CID_ERROR:
853 case SCTP_CID_ECN_CWR:
854 case SCTP_CID_ASCONF_ACK:
855 one_packet = 1;
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300856 /* Fall through */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700857
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 case SCTP_CID_SACK:
859 case SCTP_CID_HEARTBEAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 case SCTP_CID_SHUTDOWN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 case SCTP_CID_ECN_ECNE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 case SCTP_CID_ASCONF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 case SCTP_CID_FWD_TSN:
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700864 status = sctp_packet_transmit_chunk(packet, chunk,
865 one_packet);
866 if (status != SCTP_XMIT_OK) {
867 /* put the chunk back */
868 list_add(&chunk->list, &q->control_chunk_list);
Wei Yongjunbd69b982010-04-30 21:42:43 -0400869 } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
870 /* PR-SCTP C5) If a FORWARD TSN is sent, the
871 * sender MUST assure that at least one T3-rtx
872 * timer is running.
873 */
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400874 sctp_transport_reset_timers(transport);
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700875 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 break;
877
878 default:
879 /* We built a chunk with an illegal type! */
880 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700881 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 }
883
884 /* Is it OK to send data chunks? */
885 switch (asoc->state) {
886 case SCTP_STATE_COOKIE_ECHOED:
887 /* Only allow bundling when this packet has a COOKIE-ECHO
888 * chunk.
889 */
890 if (!packet || !packet->has_cookie_echo)
891 break;
892
893 /* fallthru */
894 case SCTP_STATE_ESTABLISHED:
895 case SCTP_STATE_SHUTDOWN_PENDING:
896 case SCTP_STATE_SHUTDOWN_RECEIVED:
897 /*
898 * RFC 2960 6.1 Transmission of DATA Chunks
899 *
900 * C) When the time comes for the sender to transmit,
901 * before sending new DATA chunks, the sender MUST
902 * first transmit any outstanding DATA chunks which
903 * are marked for retransmission (limited by the
904 * current cwnd).
905 */
906 if (!list_empty(&q->retransmit)) {
907 if (transport == asoc->peer.retran_path)
908 goto retran;
909
910 /* Switch transports & prepare the packet. */
911
912 transport = asoc->peer.retran_path;
913
914 if (list_empty(&transport->send_ready)) {
915 list_add_tail(&transport->send_ready,
916 &transport_list);
917 }
918
919 packet = &transport->packet;
920 sctp_packet_config(packet, vtag,
921 asoc->peer.ecn_capable);
922 retran:
923 error = sctp_outq_flush_rtx(q, packet,
924 rtx_timeout, &start_timer);
925
926 if (start_timer)
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400927 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928
929 /* This can happen on COOKIE-ECHO resend. Only
930 * one chunk can get bundled with a COOKIE-ECHO.
931 */
932 if (packet->has_cookie_echo)
933 goto sctp_flush_out;
934
935 /* Don't send new data if there is still data
936 * waiting to retransmit.
937 */
938 if (!list_empty(&q->retransmit))
939 goto sctp_flush_out;
940 }
941
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500942 /* Apply Max.Burst limitation to the current transport in
943 * case it will be used for new data. We are going to
944 * rest it before we return, but we want to apply the limit
945 * to the currently queued data.
946 */
947 if (transport)
948 sctp_transport_burst_limited(transport);
949
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 /* Finally, transmit new packets. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
952 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
953 * stream identifier.
954 */
955 if (chunk->sinfo.sinfo_stream >=
956 asoc->c.sinit_num_ostreams) {
957
958 /* Mark as failed send. */
959 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
960 sctp_chunk_free(chunk);
961 continue;
962 }
963
964 /* Has this chunk expired? */
965 if (sctp_chunk_abandoned(chunk)) {
966 sctp_chunk_fail(chunk, 0);
967 sctp_chunk_free(chunk);
968 continue;
969 }
970
971 /* If there is a specified transport, use it.
972 * Otherwise, we want to use the active path.
973 */
974 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700975 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700976 ((new_transport->state == SCTP_INACTIVE) ||
977 (new_transport->state == SCTP_UNCONFIRMED)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 new_transport = asoc->peer.active_path;
979
980 /* Change packets if necessary. */
981 if (new_transport != transport) {
982 transport = new_transport;
983
984 /* Schedule to have this transport's
985 * packet flushed.
986 */
987 if (list_empty(&transport->send_ready)) {
988 list_add_tail(&transport->send_ready,
989 &transport_list);
990 }
991
992 packet = &transport->packet;
993 sctp_packet_config(packet, vtag,
994 asoc->peer.ecn_capable);
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500995 /* We've switched transports, so apply the
996 * Burst limit to the new transport.
997 */
998 sctp_transport_burst_limited(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 }
1000
1001 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
1002 q, chunk,
1003 chunk && chunk->chunk_hdr ?
1004 sctp_cname(SCTP_ST_CHUNK(
1005 chunk->chunk_hdr->type))
1006 : "Illegal Chunk");
1007
1008 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
1009 "%p skb->users %d.\n",
1010 ntohl(chunk->subh.data_hdr->tsn),
1011 chunk->skb ?chunk->skb->head : NULL,
1012 chunk->skb ?
1013 atomic_read(&chunk->skb->users) : -1);
1014
1015 /* Add the chunk to the packet. */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07001016 status = sctp_packet_transmit_chunk(packet, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
1018 switch (status) {
1019 case SCTP_XMIT_PMTU_FULL:
1020 case SCTP_XMIT_RWND_FULL:
1021 case SCTP_XMIT_NAGLE_DELAY:
1022 /* We could not append this chunk, so put
1023 * the chunk back on the output queue.
1024 */
1025 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
1026 "not transmit TSN: 0x%x, status: %d\n",
1027 ntohl(chunk->subh.data_hdr->tsn),
1028 status);
1029 sctp_outq_head_data(q, chunk);
1030 goto sctp_flush_out;
1031 break;
1032
1033 case SCTP_XMIT_OK:
Wei Yongjunb93d6472009-11-23 15:53:56 -05001034 /* The sender is in the SHUTDOWN-PENDING state,
1035 * The sender MAY set the I-bit in the DATA
1036 * chunk header.
1037 */
1038 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
1039 chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
1040
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 break;
1042
1043 default:
1044 BUG();
1045 }
1046
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001047 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 * call below will succeed all the time and add the
1049 * chunk to the transmitted list and restart the
1050 * timers.
1051 * It is possible that the call can fail under OOM
1052 * conditions.
1053 *
1054 * Is this really a problem? Won't this behave
1055 * like a lost TSN?
1056 */
1057 list_add_tail(&chunk->transmitted_list,
1058 &transport->transmitted);
1059
Vlad Yasevichd9efc222010-04-30 22:41:09 -04001060 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061
1062 q->empty = 0;
1063
1064 /* Only let one DATA chunk get bundled with a
1065 * COOKIE-ECHO chunk.
1066 */
1067 if (packet->has_cookie_echo)
1068 goto sctp_flush_out;
1069 }
1070 break;
1071
1072 default:
1073 /* Do nothing. */
1074 break;
1075 }
1076
1077sctp_flush_out:
1078
1079 /* Before returning, examine all the transports touched in
1080 * this call. Right now, we bluntly force clear all the
1081 * transports. Things might change after we implement Nagle.
1082 * But such an examination is still required.
1083 *
1084 * --xguo
1085 */
1086 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
1087 struct sctp_transport *t = list_entry(ltransport,
1088 struct sctp_transport,
1089 send_ready);
1090 packet = &t->packet;
1091 if (!sctp_packet_empty(packet))
1092 error = sctp_packet_transmit(packet);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001093
1094 /* Clear the burst limited state, if any */
1095 sctp_transport_burst_reset(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096 }
1097
1098 return error;
1099}
1100
1101/* Update unack_data based on the incoming SACK chunk */
1102static void sctp_sack_update_unack_data(struct sctp_association *assoc,
1103 struct sctp_sackhdr *sack)
1104{
1105 sctp_sack_variable_t *frags;
1106 __u16 unack_data;
1107 int i;
1108
1109 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
1110
1111 frags = sack->variable;
1112 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1113 unack_data -= ((ntohs(frags[i].gab.end) -
1114 ntohs(frags[i].gab.start) + 1));
1115 }
1116
1117 assoc->unack_data = unack_data;
1118}
1119
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120/* This is where we REALLY process a SACK.
1121 *
1122 * Process the SACK against the outqueue. Mostly, this just frees
1123 * things off the transmitted queue.
1124 */
1125int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
1126{
1127 struct sctp_association *asoc = q->asoc;
1128 struct sctp_transport *transport;
1129 struct sctp_chunk *tchunk = NULL;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001130 struct list_head *lchunk, *transport_list, *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 sctp_sack_variable_t *frags = sack->variable;
1132 __u32 sack_ctsn, ctsn, tsn;
1133 __u32 highest_tsn, highest_new_tsn;
1134 __u32 sack_a_rwnd;
1135 unsigned outstanding;
1136 struct sctp_transport *primary = asoc->peer.primary_path;
1137 int count_of_newacks = 0;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001138 int gap_ack_blocks;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001139 u8 accum_moved = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140
1141 /* Grab the association's destination address list. */
1142 transport_list = &asoc->peer.transport_addr_list;
1143
1144 sack_ctsn = ntohl(sack->cum_tsn_ack);
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001145 gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 /*
1147 * SFR-CACC algorithm:
1148 * On receipt of a SACK the sender SHOULD execute the
1149 * following statements.
1150 *
1151 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1152 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1153 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1154 * all destinations.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1156 * is set the receiver of the SACK MUST take the following actions:
1157 *
1158 * A) Initialize the cacc_saw_newack to 0 for all destination
1159 * addresses.
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001160 *
1161 * Only bother if changeover_active is set. Otherwise, this is
1162 * totally suboptimal to do on every SACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163 */
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001164 if (primary->cacc.changeover_active) {
1165 u8 clear_cycling = 0;
1166
1167 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1168 primary->cacc.changeover_active = 0;
1169 clear_cycling = 1;
1170 }
1171
1172 if (clear_cycling || gap_ack_blocks) {
1173 list_for_each_entry(transport, transport_list,
1174 transports) {
1175 if (clear_cycling)
1176 transport->cacc.cycling_changeover = 0;
1177 if (gap_ack_blocks)
1178 transport->cacc.cacc_saw_newack = 0;
1179 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180 }
1181 }
1182
1183 /* Get the highest TSN in the sack. */
1184 highest_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001185 if (gap_ack_blocks)
1186 highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001188 if (TSN_lt(asoc->highest_sacked, highest_tsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 asoc->highest_sacked = highest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001191 highest_new_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001192
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 /* Run through the retransmit queue. Credit bytes received
1194 * and free those chunks that we can.
1195 */
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001196 sctp_check_transmitted(q, &q->retransmit, NULL, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197
1198 /* Run through the transmitted queue.
1199 * Credit bytes received and free those chunks which we can.
1200 *
1201 * This is a MASSIVE candidate for optimization.
1202 */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001203 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 sctp_check_transmitted(q, &transport->transmitted,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001205 transport, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 /*
1207 * SFR-CACC algorithm:
1208 * C) Let count_of_newacks be the number of
1209 * destinations for which cacc_saw_newack is set.
1210 */
1211 if (transport->cacc.cacc_saw_newack)
1212 count_of_newacks ++;
1213 }
1214
Vlad Yasevichea862c82010-04-30 22:41:10 -04001215 /* Move the Cumulative TSN Ack Point if appropriate. */
1216 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) {
1217 asoc->ctsn_ack_point = sack_ctsn;
1218 accum_moved = 1;
1219 }
1220
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001221 if (gap_ack_blocks) {
Vlad Yasevichea862c82010-04-30 22:41:10 -04001222
1223 if (asoc->fast_recovery && accum_moved)
1224 highest_new_tsn = highest_tsn;
1225
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
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 /* Update unack_data field in the assoc. */
1232 sctp_sack_update_unack_data(asoc, sack);
1233
1234 ctsn = asoc->ctsn_ack_point;
1235
1236 /* Throw away stuff rotting on the sack queue. */
1237 list_for_each_safe(lchunk, temp, &q->sacked) {
1238 tchunk = list_entry(lchunk, struct sctp_chunk,
1239 transmitted_list);
1240 tsn = ntohl(tchunk->subh.data_hdr->tsn);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001241 if (TSN_lte(tsn, ctsn)) {
1242 list_del_init(&tchunk->transmitted_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001243 sctp_chunk_free(tchunk);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001244 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 }
1246
1247 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1248 * number of bytes still outstanding after processing the
1249 * Cumulative TSN Ack and the Gap Ack Blocks.
1250 */
1251
1252 sack_a_rwnd = ntohl(sack->a_rwnd);
1253 outstanding = q->outstanding_bytes;
1254
1255 if (outstanding < sack_a_rwnd)
1256 sack_a_rwnd -= outstanding;
1257 else
1258 sack_a_rwnd = 0;
1259
1260 asoc->peer.rwnd = sack_a_rwnd;
1261
1262 sctp_generate_fwdtsn(q, sack_ctsn);
1263
1264 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001265 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1267 "%p is 0x%x. Adv peer ack point: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001268 __func__, asoc, ctsn, asoc->adv_peer_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269
1270 /* See if all chunks are acked.
1271 * Make sure the empty queue handler will get run later.
1272 */
David S. Miller79af02c2005-07-08 21:47:49 -07001273 q->empty = (list_empty(&q->out_chunk_list) &&
David S. Miller79af02c2005-07-08 21:47:49 -07001274 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 if (!q->empty)
1276 goto finish;
1277
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001278 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 q->empty = q->empty && list_empty(&transport->transmitted);
1280 if (!q->empty)
1281 goto finish;
1282 }
1283
1284 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1285finish:
1286 return q->empty;
1287}
1288
1289/* Is the outqueue empty? */
1290int sctp_outq_is_empty(const struct sctp_outq *q)
1291{
1292 return q->empty;
1293}
1294
1295/********************************************************************
1296 * 2nd Level Abstractions
1297 ********************************************************************/
1298
1299/* Go through a transport's transmitted list or the association's retransmit
1300 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1301 * The retransmit list will not have an associated transport.
1302 *
1303 * I added coherent debug information output. --xguo
1304 *
1305 * Instead of printing 'sacked' or 'kept' for each TSN on the
1306 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1307 * KEPT TSN6-TSN7, etc.
1308 */
1309static void sctp_check_transmitted(struct sctp_outq *q,
1310 struct list_head *transmitted_queue,
1311 struct sctp_transport *transport,
1312 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001313 __u32 *highest_new_tsn_in_sack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314{
1315 struct list_head *lchunk;
1316 struct sctp_chunk *tchunk;
1317 struct list_head tlist;
1318 __u32 tsn;
1319 __u32 sack_ctsn;
1320 __u32 rtt;
1321 __u8 restart_timer = 0;
1322 int bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001323 int migrate_bytes = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324
1325 /* These state variables are for coherent debug output. --xguo */
1326
1327#if SCTP_DEBUG
1328 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1329 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1330 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1331 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1332
1333 /* 0 : The last TSN was ACKed.
1334 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1335 * -1: We need to initialize.
1336 */
1337 int dbg_prt_state = -1;
1338#endif /* SCTP_DEBUG */
1339
1340 sack_ctsn = ntohl(sack->cum_tsn_ack);
1341
1342 INIT_LIST_HEAD(&tlist);
1343
1344 /* The while loop will skip empty transmitted queues. */
1345 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1346 tchunk = list_entry(lchunk, struct sctp_chunk,
1347 transmitted_list);
1348
1349 if (sctp_chunk_abandoned(tchunk)) {
1350 /* Move the chunk to abandoned list. */
1351 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001352
1353 /* If this chunk has not been acked, stop
1354 * considering it as 'outstanding'.
1355 */
1356 if (!tchunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001357 if (tchunk->transport)
1358 tchunk->transport->flight_size -=
1359 sctp_data_size(tchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001360 q->outstanding_bytes -= sctp_data_size(tchunk);
1361 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 continue;
1363 }
1364
1365 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1366 if (sctp_acked(sack, tsn)) {
1367 /* If this queue is the retransmit queue, the
1368 * retransmit timer has already reclaimed
1369 * the outstanding bytes for this chunk, so only
1370 * count bytes associated with a transport.
1371 */
1372 if (transport) {
1373 /* If this chunk is being used for RTT
1374 * measurement, calculate the RTT and update
1375 * the RTO using this value.
1376 *
1377 * 6.3.1 C5) Karn's algorithm: RTT measurements
1378 * MUST NOT be made using packets that were
1379 * retransmitted (and thus for which it is
1380 * ambiguous whether the reply was for the
1381 * first instance of the packet or a later
1382 * instance).
1383 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001384 if (!tchunk->tsn_gap_acked &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001386 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387 rtt = jiffies - tchunk->sent_at;
1388 sctp_transport_update_rto(transport,
1389 rtt);
1390 }
1391 }
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001392
1393 /* If the chunk hasn't been marked as ACKED,
1394 * mark it and account bytes_acked if the
1395 * chunk had a valid transport (it will not
1396 * have a transport if ASCONF had deleted it
1397 * while DATA was outstanding).
1398 */
1399 if (!tchunk->tsn_gap_acked) {
1400 tchunk->tsn_gap_acked = 1;
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001401 *highest_new_tsn_in_sack = tsn;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001402 bytes_acked += sctp_data_size(tchunk);
1403 if (!tchunk->transport)
1404 migrate_bytes += sctp_data_size(tchunk);
1405 }
1406
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001407 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408 /* RFC 2960 6.3.2 Retransmission Timer Rules
1409 *
1410 * R3) Whenever a SACK is received
1411 * that acknowledges the DATA chunk
1412 * with the earliest outstanding TSN
1413 * for that address, restart T3-rtx
1414 * timer for that address with its
1415 * current RTO.
1416 */
1417 restart_timer = 1;
1418
1419 if (!tchunk->tsn_gap_acked) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420 /*
1421 * SFR-CACC algorithm:
1422 * 2) If the SACK contains gap acks
1423 * and the flag CHANGEOVER_ACTIVE is
1424 * set the receiver of the SACK MUST
1425 * take the following action:
1426 *
1427 * B) For each TSN t being acked that
1428 * has not been acked in any SACK so
1429 * far, set cacc_saw_newack to 1 for
1430 * the destination that the TSN was
1431 * sent to.
1432 */
1433 if (transport &&
1434 sack->num_gap_ack_blocks &&
1435 q->asoc->peer.primary_path->cacc.
1436 changeover_active)
1437 transport->cacc.cacc_saw_newack
1438 = 1;
1439 }
1440
1441 list_add_tail(&tchunk->transmitted_list,
1442 &q->sacked);
1443 } else {
1444 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1445 * M2) Each time a SACK arrives reporting
1446 * 'Stray DATA chunk(s)' record the highest TSN
1447 * reported as newly acknowledged, call this
1448 * value 'HighestTSNinSack'. A newly
1449 * acknowledged DATA chunk is one not
1450 * previously acknowledged in a SACK.
1451 *
1452 * When the SCTP sender of data receives a SACK
1453 * chunk that acknowledges, for the first time,
1454 * the receipt of a DATA chunk, all the still
1455 * unacknowledged DATA chunks whose TSN is
1456 * older than that newly acknowledged DATA
1457 * chunk, are qualified as 'Stray DATA chunks'.
1458 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459 list_add_tail(lchunk, &tlist);
1460 }
1461
1462#if SCTP_DEBUG
1463 switch (dbg_prt_state) {
1464 case 0: /* last TSN was ACKed */
1465 if (dbg_last_ack_tsn + 1 == tsn) {
1466 /* This TSN belongs to the
1467 * current ACK range.
1468 */
1469 break;
1470 }
1471
1472 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1473 /* Display the end of the
1474 * current range.
1475 */
Joe Perches145ce502010-08-24 13:21:08 +00001476 SCTP_DEBUG_PRINTK_CONT("-%08x",
1477 dbg_last_ack_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001478 }
1479
1480 /* Start a new range. */
Joe Perches145ce502010-08-24 13:21:08 +00001481 SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001482 dbg_ack_tsn = tsn;
1483 break;
1484
1485 case 1: /* The last TSN was NOT ACKed. */
1486 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1487 /* Display the end of current range. */
Joe Perches145ce502010-08-24 13:21:08 +00001488 SCTP_DEBUG_PRINTK_CONT("-%08x",
1489 dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 }
1491
Joe Perches145ce502010-08-24 13:21:08 +00001492 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001493
1494 /* FALL THROUGH... */
1495 default:
1496 /* This is the first-ever TSN we examined. */
1497 /* Start a new range of ACK-ed TSNs. */
1498 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1499 dbg_prt_state = 0;
1500 dbg_ack_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001501 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502
1503 dbg_last_ack_tsn = tsn;
1504#endif /* SCTP_DEBUG */
1505
1506 } else {
1507 if (tchunk->tsn_gap_acked) {
1508 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1509 "data TSN: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001510 __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 tsn);
1512 tchunk->tsn_gap_acked = 0;
1513
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001514 if (tchunk->transport)
1515 bytes_acked -= sctp_data_size(tchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516
1517 /* RFC 2960 6.3.2 Retransmission Timer Rules
1518 *
1519 * R4) Whenever a SACK is received missing a
1520 * TSN that was previously acknowledged via a
1521 * Gap Ack Block, start T3-rtx for the
1522 * destination address to which the DATA
1523 * chunk was originally
1524 * transmitted if it is not already running.
1525 */
1526 restart_timer = 1;
1527 }
1528
1529 list_add_tail(lchunk, &tlist);
1530
1531#if SCTP_DEBUG
1532 /* See the above comments on ACK-ed TSNs. */
1533 switch (dbg_prt_state) {
1534 case 1:
1535 if (dbg_last_kept_tsn + 1 == tsn)
1536 break;
1537
1538 if (dbg_last_kept_tsn != dbg_kept_tsn)
Joe Perches145ce502010-08-24 13:21:08 +00001539 SCTP_DEBUG_PRINTK_CONT("-%08x",
1540 dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001541
Joe Perches145ce502010-08-24 13:21:08 +00001542 SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001543 dbg_kept_tsn = tsn;
1544 break;
1545
1546 case 0:
1547 if (dbg_last_ack_tsn != dbg_ack_tsn)
Joe Perches145ce502010-08-24 13:21:08 +00001548 SCTP_DEBUG_PRINTK_CONT("-%08x",
1549 dbg_last_ack_tsn);
1550 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551
1552 /* FALL THROUGH... */
1553 default:
1554 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1555 dbg_prt_state = 1;
1556 dbg_kept_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001557 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558
1559 dbg_last_kept_tsn = tsn;
1560#endif /* SCTP_DEBUG */
1561 }
1562 }
1563
1564#if SCTP_DEBUG
1565 /* Finish off the last range, displaying its ending TSN. */
1566 switch (dbg_prt_state) {
1567 case 0:
1568 if (dbg_last_ack_tsn != dbg_ack_tsn) {
Joe Perches145ce502010-08-24 13:21:08 +00001569 SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_ack_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570 } else {
Joe Perches145ce502010-08-24 13:21:08 +00001571 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572 }
1573 break;
1574
1575 case 1:
1576 if (dbg_last_kept_tsn != dbg_kept_tsn) {
Joe Perches145ce502010-08-24 13:21:08 +00001577 SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 } else {
Joe Perches145ce502010-08-24 13:21:08 +00001579 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001580 }
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001581 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582#endif /* SCTP_DEBUG */
1583 if (transport) {
1584 if (bytes_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001585 /* We may have counted DATA that was migrated
1586 * to this transport due to DEL-IP operation.
1587 * Subtract those bytes, since the were never
1588 * send on this transport and shouldn't be
1589 * credited to this transport.
1590 */
1591 bytes_acked -= migrate_bytes;
1592
Linus Torvalds1da177e2005-04-16 15:20:36 -07001593 /* 8.2. When an outstanding TSN is acknowledged,
1594 * the endpoint shall clear the error counter of
1595 * the destination transport address to which the
1596 * DATA chunk was last sent.
1597 * The association's overall error counter is
1598 * also cleared.
1599 */
1600 transport->error_count = 0;
1601 transport->asoc->overall_error_count = 0;
1602
1603 /* Mark the destination transport address as
1604 * active if it is not so marked.
1605 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001606 if ((transport->state == SCTP_INACTIVE) ||
1607 (transport->state == SCTP_UNCONFIRMED)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608 sctp_assoc_control_transport(
1609 transport->asoc,
1610 transport,
1611 SCTP_TRANSPORT_UP,
1612 SCTP_RECEIVED_SACK);
1613 }
1614
1615 sctp_transport_raise_cwnd(transport, sack_ctsn,
1616 bytes_acked);
1617
1618 transport->flight_size -= bytes_acked;
Gui Jianfeng8b73a072008-04-17 14:22:18 -07001619 if (transport->flight_size == 0)
1620 transport->partial_bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001621 q->outstanding_bytes -= bytes_acked + migrate_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622 } else {
1623 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1624 * When a sender is doing zero window probing, it
1625 * should not timeout the association if it continues
1626 * to receive new packets from the receiver. The
1627 * reason is that the receiver MAY keep its window
1628 * closed for an indefinite time.
1629 * A sender is doing zero window probing when the
1630 * receiver's advertised window is zero, and there is
1631 * only one data chunk in flight to the receiver.
1632 */
1633 if (!q->asoc->peer.rwnd &&
1634 !list_empty(&tlist) &&
1635 (sack_ctsn+2 == q->asoc->next_tsn)) {
1636 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1637 "window probe: %u\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001638 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001639 q->asoc->overall_error_count = 0;
1640 transport->error_count = 0;
1641 }
1642 }
1643
1644 /* RFC 2960 6.3.2 Retransmission Timer Rules
1645 *
1646 * R2) Whenever all outstanding data sent to an address have
1647 * been acknowledged, turn off the T3-rtx timer of that
1648 * address.
1649 */
1650 if (!transport->flight_size) {
1651 if (timer_pending(&transport->T3_rtx_timer) &&
1652 del_timer(&transport->T3_rtx_timer)) {
1653 sctp_transport_put(transport);
1654 }
1655 } else if (restart_timer) {
1656 if (!mod_timer(&transport->T3_rtx_timer,
1657 jiffies + transport->rto))
1658 sctp_transport_hold(transport);
1659 }
1660 }
1661
1662 list_splice(&tlist, transmitted_queue);
1663}
1664
1665/* Mark chunks as missing and consequently may get retransmitted. */
1666static void sctp_mark_missing(struct sctp_outq *q,
1667 struct list_head *transmitted_queue,
1668 struct sctp_transport *transport,
1669 __u32 highest_new_tsn_in_sack,
1670 int count_of_newacks)
1671{
1672 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 __u32 tsn;
1674 char do_fast_retransmit = 0;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001675 struct sctp_association *asoc = q->asoc;
1676 struct sctp_transport *primary = asoc->peer.primary_path;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001678 list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679
Linus Torvalds1da177e2005-04-16 15:20:36 -07001680 tsn = ntohl(chunk->subh.data_hdr->tsn);
1681
1682 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1683 * 'Unacknowledged TSN's', if the TSN number of an
1684 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1685 * value, increment the 'TSN.Missing.Report' count on that
1686 * chunk if it has NOT been fast retransmitted or marked for
1687 * fast retransmit already.
1688 */
Neil Hormanc226ef92008-07-25 12:44:09 -04001689 if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 !chunk->tsn_gap_acked &&
1691 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1692
1693 /* SFR-CACC may require us to skip marking
1694 * this chunk as missing.
1695 */
Vlad Yasevichf246a7b2011-04-18 19:13:56 +00001696 if (!transport || !sctp_cacc_skip(primary,
1697 chunk->transport,
1698 count_of_newacks, tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 chunk->tsn_missing_report++;
1700
1701 SCTP_DEBUG_PRINTK(
1702 "%s: TSN 0x%x missing counter: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001703 __func__, tsn,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704 chunk->tsn_missing_report);
1705 }
1706 }
1707 /*
1708 * M4) If any DATA chunk is found to have a
1709 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001710 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 * retransmission and start the fast retransmit procedure.
1712 */
1713
Vlad Yasevich27852c22006-02-02 16:57:31 -08001714 if (chunk->tsn_missing_report >= 3) {
Neil Hormanc226ef92008-07-25 12:44:09 -04001715 chunk->fast_retransmit = SCTP_NEED_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716 do_fast_retransmit = 1;
1717 }
1718 }
1719
1720 if (transport) {
1721 if (do_fast_retransmit)
1722 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1723
1724 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1725 "ssthresh: %d, flight_size: %d, pba: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001726 __func__, transport, transport->cwnd,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001727 transport->ssthresh, transport->flight_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001728 transport->partial_bytes_acked);
1729 }
1730}
1731
1732/* Is the given TSN acked by this packet? */
1733static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1734{
1735 int i;
1736 sctp_sack_variable_t *frags;
1737 __u16 gap;
1738 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1739
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001740 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 goto pass;
1742
1743 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1744 *
1745 * Gap Ack Blocks:
1746 * These fields contain the Gap Ack Blocks. They are repeated
1747 * for each Gap Ack Block up to the number of Gap Ack Blocks
1748 * defined in the Number of Gap Ack Blocks field. All DATA
1749 * chunks with TSNs greater than or equal to (Cumulative TSN
1750 * Ack + Gap Ack Block Start) and less than or equal to
1751 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1752 * Block are assumed to have been received correctly.
1753 */
1754
1755 frags = sack->variable;
1756 gap = tsn - ctsn;
1757 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1758 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1759 TSN_lte(gap, ntohs(frags[i].gab.end)))
1760 goto pass;
1761 }
1762
1763 return 0;
1764pass:
1765 return 1;
1766}
1767
1768static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001769 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770{
1771 int i;
1772
1773 for (i = 0; i < nskips; i++) {
1774 if (skiplist[i].stream == stream)
1775 return i;
1776 }
1777 return i;
1778}
1779
1780/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1781static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1782{
1783 struct sctp_association *asoc = q->asoc;
1784 struct sctp_chunk *ftsn_chunk = NULL;
1785 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1786 int nskips = 0;
1787 int skip_pos = 0;
1788 __u32 tsn;
1789 struct sctp_chunk *chunk;
1790 struct list_head *lchunk, *temp;
1791
Wei Yongjun76595022009-03-12 09:49:19 +00001792 if (!asoc->peer.prsctp_capable)
1793 return;
1794
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1796 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001797 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001798 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1799 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1800 */
1801 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1802 asoc->adv_peer_ack_point = ctsn;
1803
1804 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1805 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1806 * the chunk next in the out-queue space is marked as "abandoned" as
1807 * shown in the following example:
1808 *
1809 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1810 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001811 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1813 * normal SACK processing local advancement
1814 * ... ...
1815 * Adv.Ack.Pt-> 102 acked 102 acked
1816 * 103 abandoned 103 abandoned
1817 * 104 abandoned Adv.Ack.P-> 104 abandoned
1818 * 105 105
1819 * 106 acked 106 acked
1820 * ... ...
1821 *
1822 * In this example, the data sender successfully advanced the
1823 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1824 */
1825 list_for_each_safe(lchunk, temp, &q->abandoned) {
1826 chunk = list_entry(lchunk, struct sctp_chunk,
1827 transmitted_list);
1828 tsn = ntohl(chunk->subh.data_hdr->tsn);
1829
1830 /* Remove any chunks in the abandoned queue that are acked by
1831 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001832 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001833 if (TSN_lte(tsn, ctsn)) {
1834 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835 sctp_chunk_free(chunk);
1836 } else {
1837 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1838 asoc->adv_peer_ack_point = tsn;
1839 if (chunk->chunk_hdr->flags &
1840 SCTP_DATA_UNORDERED)
1841 continue;
1842 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1843 nskips,
1844 chunk->subh.data_hdr->stream);
1845 ftsn_skip_arr[skip_pos].stream =
1846 chunk->subh.data_hdr->stream;
1847 ftsn_skip_arr[skip_pos].ssn =
1848 chunk->subh.data_hdr->ssn;
1849 if (skip_pos == nskips)
1850 nskips++;
1851 if (nskips == 10)
1852 break;
1853 } else
1854 break;
1855 }
1856 }
1857
1858 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1859 * is greater than the Cumulative TSN ACK carried in the received
1860 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1861 * chunk containing the latest value of the
1862 * "Advanced.Peer.Ack.Point".
1863 *
1864 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1865 * list each stream and sequence number in the forwarded TSN. This
1866 * information will enable the receiver to easily find any
1867 * stranded TSN's waiting on stream reorder queues. Each stream
1868 * SHOULD only be reported once; this means that if multiple
1869 * abandoned messages occur in the same stream then only the
1870 * highest abandoned stream sequence number is reported. If the
1871 * total size of the FORWARD TSN does NOT fit in a single MTU then
1872 * the sender of the FORWARD TSN SHOULD lower the
1873 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1874 * single MTU.
1875 */
1876 if (asoc->adv_peer_ack_point > ctsn)
1877 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001878 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879
1880 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001881 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001882 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1883 }
1884}