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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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090053#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070054#include <net/sock.h> /* For skb_set_owner_w */
55
56#include <net/sctp/sctp.h>
57#include <net/sctp/sm.h>
58
59/* Declare internal functions here. */
60static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
61static void sctp_check_transmitted(struct sctp_outq *q,
62 struct list_head *transmitted_queue,
63 struct sctp_transport *transport,
64 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -040065 __u32 *highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67static void sctp_mark_missing(struct sctp_outq *q,
68 struct list_head *transmitted_queue,
69 struct sctp_transport *transport,
70 __u32 highest_new_tsn,
71 int count_of_newacks);
72
73static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
74
Adrian Bunkabd0b1982008-07-22 14:20:45 -070075static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout);
76
Linus Torvalds1da177e2005-04-16 15:20:36 -070077/* Add data to the front of the queue. */
78static inline void sctp_outq_head_data(struct sctp_outq *q,
79 struct sctp_chunk *ch)
80{
David S. Miller79af02c2005-07-08 21:47:49 -070081 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083}
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105}
106
107/*
108 * SFR-CACC algorithm:
109 * D) If count_of_newacks is greater than or equal to 2
110 * and t was not sent to the current primary then the
111 * sender MUST NOT increment missing report count for t.
112 */
113static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
114 struct sctp_transport *transport,
115 int count_of_newacks)
116{
117 if (count_of_newacks >=2 && transport != primary)
118 return 1;
119 return 0;
120}
121
122/*
123 * SFR-CACC algorithm:
124 * F) If count_of_newacks is less than 2, let d be the
125 * destination to which t was sent. If cacc_saw_newack
126 * is 0 for destination d, then the sender MUST NOT
127 * increment missing report count for t.
128 */
129static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
130 int count_of_newacks)
131{
132 if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack)
133 return 1;
134 return 0;
135}
136
137/*
138 * SFR-CACC algorithm:
139 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
140 * execute steps C, D, F.
141 *
142 * C has been implemented in sctp_outq_sack
143 */
144static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
145 struct sctp_transport *transport,
146 int count_of_newacks)
147{
148 if (!primary->cacc.cycling_changeover) {
149 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
150 return 1;
151 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
152 return 1;
153 return 0;
154 }
155 return 0;
156}
157
158/*
159 * SFR-CACC algorithm:
160 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
161 * than next_tsn_at_change of the current primary, then
162 * the sender MUST NOT increment missing report count
163 * for t.
164 */
165static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
166{
167 if (primary->cacc.cycling_changeover &&
168 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
169 return 1;
170 return 0;
171}
172
173/*
174 * SFR-CACC algorithm:
175 * 3) If the missing report count for TSN t is to be
176 * incremented according to [RFC2960] and
177 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
178 * then the sender MUST futher execute steps 3.1 and
179 * 3.2 to determine if the missing report count for
180 * TSN t SHOULD NOT be incremented.
181 *
182 * 3.3) If 3.1 and 3.2 do not dictate that the missing
183 * report count for t should not be incremented, then
184 * the sender SOULD increment missing report count for
185 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
186 */
187static inline int sctp_cacc_skip(struct sctp_transport *primary,
188 struct sctp_transport *transport,
189 int count_of_newacks,
190 __u32 tsn)
191{
192 if (primary->cacc.changeover_active &&
Joe Perchesf64f9e72009-11-29 16:55:45 -0800193 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) ||
194 sctp_cacc_skip_3_2(primary, tsn)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 return 1;
196 return 0;
197}
198
199/* Initialize an existing sctp_outq. This does the boring stuff.
200 * You still need to define handlers if you really want to DO
201 * something with this structure...
202 */
203void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
204{
205 q->asoc = asoc;
David S. Miller79af02c2005-07-08 21:47:49 -0700206 INIT_LIST_HEAD(&q->out_chunk_list);
207 INIT_LIST_HEAD(&q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 INIT_LIST_HEAD(&q->retransmit);
209 INIT_LIST_HEAD(&q->sacked);
210 INIT_LIST_HEAD(&q->abandoned);
211
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700212 q->fast_rtx = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 q->outstanding_bytes = 0;
214 q->empty = 1;
215 q->cork = 0;
216
217 q->malloced = 0;
218 q->out_qlen = 0;
219}
220
221/* Free the outqueue structure and any related pending chunks.
222 */
223void sctp_outq_teardown(struct sctp_outq *q)
224{
225 struct sctp_transport *transport;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700226 struct list_head *lchunk, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700227 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 /* Throw away unacknowledged chunks. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700230 list_for_each_entry(transport, &q->asoc->peer.transport_addr_list,
231 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
233 chunk = list_entry(lchunk, struct sctp_chunk,
234 transmitted_list);
235 /* Mark as part of a failed message. */
236 sctp_chunk_fail(chunk, q->error);
237 sctp_chunk_free(chunk);
238 }
239 }
240
241 /* Throw away chunks that have been gap ACKed. */
242 list_for_each_safe(lchunk, temp, &q->sacked) {
243 list_del_init(lchunk);
244 chunk = list_entry(lchunk, struct sctp_chunk,
245 transmitted_list);
246 sctp_chunk_fail(chunk, q->error);
247 sctp_chunk_free(chunk);
248 }
249
250 /* Throw away any chunks in the retransmit queue. */
251 list_for_each_safe(lchunk, temp, &q->retransmit) {
252 list_del_init(lchunk);
253 chunk = list_entry(lchunk, struct sctp_chunk,
254 transmitted_list);
255 sctp_chunk_fail(chunk, q->error);
256 sctp_chunk_free(chunk);
257 }
258
259 /* Throw away any chunks that are in the abandoned queue. */
260 list_for_each_safe(lchunk, temp, &q->abandoned) {
261 list_del_init(lchunk);
262 chunk = list_entry(lchunk, struct sctp_chunk,
263 transmitted_list);
264 sctp_chunk_fail(chunk, q->error);
265 sctp_chunk_free(chunk);
266 }
267
268 /* Throw away any leftover data chunks. */
269 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
270
271 /* Mark as send failure. */
272 sctp_chunk_fail(chunk, q->error);
273 sctp_chunk_free(chunk);
274 }
275
276 q->error = 0;
277
278 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700279 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
280 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700282 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283}
284
285/* Free the outqueue structure and any related pending chunks. */
286void sctp_outq_free(struct sctp_outq *q)
287{
288 /* Throw away leftover chunks. */
289 sctp_outq_teardown(q);
290
291 /* If we were kmalloc()'d, free the memory. */
292 if (q->malloced)
293 kfree(q);
294}
295
296/* Put a new chunk in an sctp_outq. */
297int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
298{
299 int error = 0;
300
301 SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
302 q, chunk, chunk && chunk->chunk_hdr ?
303 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
304 : "Illegal Chunk");
305
306 /* If it is data, queue it up, otherwise, send it
307 * immediately.
308 */
Shan Weiec7b9512010-04-30 22:41:09 -0400309 if (sctp_chunk_is_data(chunk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 /* Is it OK to queue data chunks? */
311 /* From 9. Termination of Association
312 *
313 * When either endpoint performs a shutdown, the
314 * association on each peer will stop accepting new
315 * data from its user and only deliver data in queue
316 * at the time of sending or receiving the SHUTDOWN
317 * chunk.
318 */
319 switch (q->asoc->state) {
320 case SCTP_STATE_EMPTY:
321 case SCTP_STATE_CLOSED:
322 case SCTP_STATE_SHUTDOWN_PENDING:
323 case SCTP_STATE_SHUTDOWN_SENT:
324 case SCTP_STATE_SHUTDOWN_RECEIVED:
325 case SCTP_STATE_SHUTDOWN_ACK_SENT:
326 /* Cannot send after transport endpoint shutdown */
327 error = -ESHUTDOWN;
328 break;
329
330 default:
331 SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
332 q, chunk, chunk && chunk->chunk_hdr ?
333 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
334 : "Illegal Chunk");
335
336 sctp_outq_tail_data(q, chunk);
337 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
338 SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
339 else
340 SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
341 q->empty = 0;
342 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700343 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700345 list_add_tail(&chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
347 }
348
349 if (error < 0)
350 return error;
351
352 if (!q->cork)
353 error = sctp_outq_flush(q, 0);
354
355 return error;
356}
357
358/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
359 * and the abandoned list are in ascending order.
360 */
361static void sctp_insert_list(struct list_head *head, struct list_head *new)
362{
363 struct list_head *pos;
364 struct sctp_chunk *nchunk, *lchunk;
365 __u32 ntsn, ltsn;
366 int done = 0;
367
368 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
369 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
370
371 list_for_each(pos, head) {
372 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
373 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
374 if (TSN_lt(ntsn, ltsn)) {
375 list_add(new, pos->prev);
376 done = 1;
377 break;
378 }
379 }
380 if (!done)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900381 list_add_tail(new, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382}
383
384/* Mark all the eligible packets on a transport for retransmission. */
385void sctp_retransmit_mark(struct sctp_outq *q,
386 struct sctp_transport *transport,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400387 __u8 reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388{
389 struct list_head *lchunk, *ltemp;
390 struct sctp_chunk *chunk;
391
392 /* Walk through the specified transmitted queue. */
393 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
394 chunk = list_entry(lchunk, struct sctp_chunk,
395 transmitted_list);
396
397 /* If the chunk is abandoned, move it to abandoned list. */
398 if (sctp_chunk_abandoned(chunk)) {
399 list_del_init(lchunk);
400 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800401
402 /* If this chunk has not been previousely acked,
403 * stop considering it 'outstanding'. Our peer
404 * will most likely never see it since it will
405 * not be retransmitted
406 */
407 if (!chunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400408 if (chunk->transport)
409 chunk->transport->flight_size -=
410 sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800411 q->outstanding_bytes -= sctp_data_size(chunk);
412 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
413 sizeof(struct sk_buff));
414 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 continue;
416 }
417
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400418 /* If we are doing retransmission due to a timeout or pmtu
419 * discovery, only the chunks that are not yet acked should
420 * be added to the retransmit queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400422 if ((reason == SCTP_RTXR_FAST_RTX &&
Neil Hormanc226ef92008-07-25 12:44:09 -0400423 (chunk->fast_retransmit == SCTP_NEED_FRTX)) ||
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400424 (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 /* RFC 2960 6.2.1 Processing a Received SACK
426 *
427 * C) Any time a DATA chunk is marked for
428 * retransmission (via either T3-rtx timer expiration
429 * (Section 6.3.3) or via fast retransmit
430 * (Section 7.2.4)), add the data size of those
431 * chunks to the rwnd.
432 */
Sridhar Samudralacd497882006-09-29 17:09:05 -0700433 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
434 sizeof(struct sk_buff));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 q->outstanding_bytes -= sctp_data_size(chunk);
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400436 if (chunk->transport)
437 transport->flight_size -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
439 /* sctpimpguide-05 Section 2.8.2
440 * M5) If a T3-rtx timer expires, the
441 * 'TSN.Missing.Report' of all affected TSNs is set
442 * to 0.
443 */
444 chunk->tsn_missing_report = 0;
445
446 /* If a chunk that is being used for RTT measurement
447 * has to be retransmitted, we cannot use this chunk
448 * anymore for RTT measurements. Reset rto_pending so
449 * that a new RTT measurement is started when a new
450 * data chunk is sent.
451 */
452 if (chunk->rtt_in_progress) {
453 chunk->rtt_in_progress = 0;
454 transport->rto_pending = 0;
455 }
456
457 /* Move the chunk to the retransmit queue. The chunks
458 * on the retransmit queue are always kept in order.
459 */
460 list_del_init(lchunk);
461 sctp_insert_list(&q->retransmit, lchunk);
462 }
463 }
464
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400465 SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 "cwnd: %d, ssthresh: %d, flight_size: %d, "
Harvey Harrison0dc47872008-03-05 20:47:47 -0800467 "pba: %d\n", __func__,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400468 transport, reason,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 transport->cwnd, transport->ssthresh,
470 transport->flight_size,
471 transport->partial_bytes_acked);
472
473}
474
475/* Mark all the eligible packets on a transport for retransmission and force
476 * one packet out.
477 */
478void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
479 sctp_retransmit_reason_t reason)
480{
481 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
483 switch(reason) {
484 case SCTP_RTXR_T3_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700485 SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
487 /* Update the retran path if the T3-rtx timer has expired for
488 * the current retran path.
489 */
490 if (transport == transport->asoc->peer.retran_path)
491 sctp_assoc_update_retran_path(transport->asoc);
Neil Horman58fbbed2008-02-29 11:40:56 -0800492 transport->asoc->rtx_data_chunks +=
493 transport->asoc->unack_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 break;
495 case SCTP_RTXR_FAST_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700496 SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700498 q->fast_rtx = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 break;
500 case SCTP_RTXR_PMTUD:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700501 SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 break;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400503 case SCTP_RTXR_T1_RTX:
504 SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS);
Neil Horman58fbbed2008-02-29 11:40:56 -0800505 transport->asoc->init_retries++;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400506 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700507 default:
508 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 }
510
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400511 sctp_retransmit_mark(q, transport, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
513 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
514 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
515 * following the procedures outlined in C1 - C5.
516 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700517 if (reason == SCTP_RTXR_T3_RTX)
518 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700520 /* Flush the queues only on timeout, since fast_rtx is only
521 * triggered during sack processing and the queue
522 * will be flushed at the end.
523 */
524 if (reason != SCTP_RTXR_FAST_RTX)
525 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526
527 if (error)
528 q->asoc->base.sk->sk_err = -error;
529}
530
531/*
532 * Transmit DATA chunks on the retransmit queue. Upon return from
533 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
534 * need to be transmitted by the caller.
535 * We assume that pkt->transport has already been set.
536 *
537 * The return value is a normal kernel error return value.
538 */
539static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
540 int rtx_timeout, int *start_timer)
541{
542 struct list_head *lqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 struct sctp_transport *transport = pkt->transport;
544 sctp_xmit_t status;
545 struct sctp_chunk *chunk, *chunk1;
546 struct sctp_association *asoc;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700547 int fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 int error = 0;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700549 int timer = 0;
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700550 int done = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
552 asoc = q->asoc;
553 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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
581 /* Make sure that Gap Acked TSNs are not retransmitted. A
582 * simple approach is just to move such TSNs out of the
583 * way and into a 'transmitted' queue and skip to the
584 * next chunk.
585 */
586 if (chunk->tsn_gap_acked) {
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700587 list_del(&chunk->transmitted_list);
588 list_add_tail(&chunk->transmitted_list,
589 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 continue;
591 }
592
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700593 /* If we are doing fast retransmit, ignore non-fast_rtransmit
594 * chunks
595 */
596 if (fast_rtx && !chunk->fast_retransmit)
597 continue;
598
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400599redo:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 /* Attempt to append this chunk to the packet. */
601 status = sctp_packet_append_chunk(pkt, chunk);
602
603 switch (status) {
604 case SCTP_XMIT_PMTU_FULL:
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400605 if (!pkt->has_data && !pkt->has_cookie_echo) {
606 /* If this packet did not contain DATA then
607 * retransmission did not happen, so do it
608 * again. We'll ignore the error here since
609 * control chunks are already freed so there
610 * is nothing we can do.
611 */
612 sctp_packet_transmit(pkt);
613 goto redo;
614 }
615
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700617 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
619 /* If we are retransmitting, we should only
620 * send a single packet.
621 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700622 if (rtx_timeout || fast_rtx)
623 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700625 /* Bundle next chunk in the next round. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 break;
627
628 case SCTP_XMIT_RWND_FULL:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900629 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700630 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
632 /* Stop sending DATA as there is no more room
633 * at the receiver.
634 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700635 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 break;
637
638 case SCTP_XMIT_NAGLE_DELAY:
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 because of nagle delay. */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700643 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 break;
645
646 default:
647 /* The append was successful, so add this chunk to
648 * the transmitted list.
649 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700650 list_del(&chunk->transmitted_list);
651 list_add_tail(&chunk->transmitted_list,
652 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900654 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 * after it is retransmitted.
656 */
Neil Hormanc226ef92008-07-25 12:44:09 -0400657 if (chunk->fast_retransmit == SCTP_NEED_FRTX)
658 chunk->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 q->empty = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700662 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700664 /* Set the timer if there were no errors */
665 if (!error && !timer)
666 timer = 1;
667
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700668 if (done)
669 break;
670 }
671
672 /* If we are here due to a retransmit timeout or a fast
673 * retransmit and if there are any chunks left in the retransmit
674 * queue that could not fit in the PMTU sized packet, they need
675 * to be marked as ineligible for a subsequent fast retransmit.
676 */
677 if (rtx_timeout || fast_rtx) {
678 list_for_each_entry(chunk1, lqueue, transmitted_list) {
Neil Hormanc226ef92008-07-25 12:44:09 -0400679 if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
680 chunk1->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 }
682 }
683
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700684 *start_timer = timer;
685
686 /* Clear fast retransmit hint */
687 if (fast_rtx)
688 q->fast_rtx = 0;
689
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 return error;
691}
692
693/* Cork the outqueue so queued chunks are really queued. */
694int sctp_outq_uncork(struct sctp_outq *q)
695{
696 int error = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500697 if (q->cork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 q->cork = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500699 error = sctp_outq_flush(q, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 return error;
701}
702
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700703
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704/*
705 * Try to flush an outqueue.
706 *
707 * Description: Send everything in q which we legally can, subject to
708 * congestion limitations.
709 * * Note: This function can be called from multiple contexts so appropriate
710 * locking concerns must be made. Today we use the sock lock to protect
711 * this function.
712 */
Adrian Bunkabd0b1982008-07-22 14:20:45 -0700713static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714{
715 struct sctp_packet *packet;
716 struct sctp_packet singleton;
717 struct sctp_association *asoc = q->asoc;
718 __u16 sport = asoc->base.bind_addr.port;
719 __u16 dport = asoc->peer.port;
720 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 struct sctp_transport *transport = NULL;
722 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700723 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 sctp_xmit_t status;
725 int error = 0;
726 int start_timer = 0;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700727 int one_packet = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728
729 /* These transports have chunks to send. */
730 struct list_head transport_list;
731 struct list_head *ltransport;
732
733 INIT_LIST_HEAD(&transport_list);
734 packet = NULL;
735
736 /*
737 * 6.10 Bundling
738 * ...
739 * When bundling control chunks with DATA chunks, an
740 * endpoint MUST place control chunks first in the outbound
741 * SCTP packet. The transmitter MUST transmit DATA chunks
742 * within a SCTP packet in increasing order of TSN.
743 * ...
744 */
745
David S. Miller79af02c2005-07-08 21:47:49 -0700746 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
747 list_del_init(&chunk->list);
748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 /* Pick the right transport to use. */
750 new_transport = chunk->transport;
751
752 if (!new_transport) {
Vlad Yasevicha08de642007-12-20 14:11:47 -0800753 /*
754 * If we have a prior transport pointer, see if
755 * the destination address of the chunk
756 * matches the destination address of the
757 * current transport. If not a match, then
758 * try to look up the transport with a given
759 * destination address. We do this because
760 * after processing ASCONFs, we may have new
761 * transports created.
762 */
763 if (transport &&
764 sctp_cmp_addr_exact(&chunk->dest,
765 &transport->ipaddr))
766 new_transport = transport;
767 else
768 new_transport = sctp_assoc_lookup_paddr(asoc,
769 &chunk->dest);
770
771 /* if we still don't have a new transport, then
772 * use the current active path.
773 */
774 if (!new_transport)
775 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700776 } else if ((new_transport->state == SCTP_INACTIVE) ||
777 (new_transport->state == SCTP_UNCONFIRMED)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700778 /* If the chunk is Heartbeat or Heartbeat Ack,
779 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 * inactive.
781 *
782 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900783 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 * A HEARTBEAT ACK is always sent to the source IP
785 * address of the IP datagram containing the
786 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900787 * ...
Vlad Yasevicha08de642007-12-20 14:11:47 -0800788 *
789 * ASCONF_ACKs also must be sent to the source.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 */
791 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
Vlad Yasevicha08de642007-12-20 14:11:47 -0800792 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
793 chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 new_transport = asoc->peer.active_path;
795 }
796
797 /* Are we switching transports?
798 * Take care of transport locks.
799 */
800 if (new_transport != transport) {
801 transport = new_transport;
802 if (list_empty(&transport->send_ready)) {
803 list_add_tail(&transport->send_ready,
804 &transport_list);
805 }
806 packet = &transport->packet;
807 sctp_packet_config(packet, vtag,
808 asoc->peer.ecn_capable);
809 }
810
811 switch (chunk->chunk_hdr->type) {
812 /*
813 * 6.10 Bundling
814 * ...
815 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
816 * COMPLETE with any other chunks. [Send them immediately.]
817 */
818 case SCTP_CID_INIT:
819 case SCTP_CID_INIT_ACK:
820 case SCTP_CID_SHUTDOWN_COMPLETE:
821 sctp_packet_init(&singleton, transport, sport, dport);
822 sctp_packet_config(&singleton, vtag, 0);
823 sctp_packet_append_chunk(&singleton, chunk);
824 error = sctp_packet_transmit(&singleton);
825 if (error < 0)
826 return error;
827 break;
828
829 case SCTP_CID_ABORT:
Gui Jianfengf4ad85c2008-04-12 18:39:34 -0700830 if (sctp_test_T_bit(chunk)) {
831 packet->vtag = asoc->c.my_vtag;
832 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700833 /* The following chunks are "response" chunks, i.e.
834 * they are generated in response to something we
835 * received. If we are sending these, then we can
836 * send only 1 packet containing these chunks.
837 */
838 case SCTP_CID_HEARTBEAT_ACK:
839 case SCTP_CID_SHUTDOWN_ACK:
840 case SCTP_CID_COOKIE_ACK:
841 case SCTP_CID_COOKIE_ECHO:
842 case SCTP_CID_ERROR:
843 case SCTP_CID_ECN_CWR:
844 case SCTP_CID_ASCONF_ACK:
845 one_packet = 1;
846 /* Fall throught */
847
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 case SCTP_CID_SACK:
849 case SCTP_CID_HEARTBEAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 case SCTP_CID_SHUTDOWN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 case SCTP_CID_ECN_ECNE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 case SCTP_CID_ASCONF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 case SCTP_CID_FWD_TSN:
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700854 status = sctp_packet_transmit_chunk(packet, chunk,
855 one_packet);
856 if (status != SCTP_XMIT_OK) {
857 /* put the chunk back */
858 list_add(&chunk->list, &q->control_chunk_list);
Wei Yongjunbd69b982010-04-30 21:42:43 -0400859 } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
860 /* PR-SCTP C5) If a FORWARD TSN is sent, the
861 * sender MUST assure that at least one T3-rtx
862 * timer is running.
863 */
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400864 sctp_transport_reset_timers(transport);
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700865 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 break;
867
868 default:
869 /* We built a chunk with an illegal type! */
870 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700871 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 }
873
874 /* Is it OK to send data chunks? */
875 switch (asoc->state) {
876 case SCTP_STATE_COOKIE_ECHOED:
877 /* Only allow bundling when this packet has a COOKIE-ECHO
878 * chunk.
879 */
880 if (!packet || !packet->has_cookie_echo)
881 break;
882
883 /* fallthru */
884 case SCTP_STATE_ESTABLISHED:
885 case SCTP_STATE_SHUTDOWN_PENDING:
886 case SCTP_STATE_SHUTDOWN_RECEIVED:
887 /*
888 * RFC 2960 6.1 Transmission of DATA Chunks
889 *
890 * C) When the time comes for the sender to transmit,
891 * before sending new DATA chunks, the sender MUST
892 * first transmit any outstanding DATA chunks which
893 * are marked for retransmission (limited by the
894 * current cwnd).
895 */
896 if (!list_empty(&q->retransmit)) {
897 if (transport == asoc->peer.retran_path)
898 goto retran;
899
900 /* Switch transports & prepare the packet. */
901
902 transport = asoc->peer.retran_path;
903
904 if (list_empty(&transport->send_ready)) {
905 list_add_tail(&transport->send_ready,
906 &transport_list);
907 }
908
909 packet = &transport->packet;
910 sctp_packet_config(packet, vtag,
911 asoc->peer.ecn_capable);
912 retran:
913 error = sctp_outq_flush_rtx(q, packet,
914 rtx_timeout, &start_timer);
915
916 if (start_timer)
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400917 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918
919 /* This can happen on COOKIE-ECHO resend. Only
920 * one chunk can get bundled with a COOKIE-ECHO.
921 */
922 if (packet->has_cookie_echo)
923 goto sctp_flush_out;
924
925 /* Don't send new data if there is still data
926 * waiting to retransmit.
927 */
928 if (!list_empty(&q->retransmit))
929 goto sctp_flush_out;
930 }
931
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500932 /* Apply Max.Burst limitation to the current transport in
933 * case it will be used for new data. We are going to
934 * rest it before we return, but we want to apply the limit
935 * to the currently queued data.
936 */
937 if (transport)
938 sctp_transport_burst_limited(transport);
939
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940 /* Finally, transmit new packets. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
942 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
943 * stream identifier.
944 */
945 if (chunk->sinfo.sinfo_stream >=
946 asoc->c.sinit_num_ostreams) {
947
948 /* Mark as failed send. */
949 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
950 sctp_chunk_free(chunk);
951 continue;
952 }
953
954 /* Has this chunk expired? */
955 if (sctp_chunk_abandoned(chunk)) {
956 sctp_chunk_fail(chunk, 0);
957 sctp_chunk_free(chunk);
958 continue;
959 }
960
961 /* If there is a specified transport, use it.
962 * Otherwise, we want to use the active path.
963 */
964 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700965 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700966 ((new_transport->state == SCTP_INACTIVE) ||
967 (new_transport->state == SCTP_UNCONFIRMED)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 new_transport = asoc->peer.active_path;
969
970 /* Change packets if necessary. */
971 if (new_transport != transport) {
972 transport = new_transport;
973
974 /* Schedule to have this transport's
975 * packet flushed.
976 */
977 if (list_empty(&transport->send_ready)) {
978 list_add_tail(&transport->send_ready,
979 &transport_list);
980 }
981
982 packet = &transport->packet;
983 sctp_packet_config(packet, vtag,
984 asoc->peer.ecn_capable);
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500985 /* We've switched transports, so apply the
986 * Burst limit to the new transport.
987 */
988 sctp_transport_burst_limited(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 }
990
991 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
992 q, chunk,
993 chunk && chunk->chunk_hdr ?
994 sctp_cname(SCTP_ST_CHUNK(
995 chunk->chunk_hdr->type))
996 : "Illegal Chunk");
997
998 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
999 "%p skb->users %d.\n",
1000 ntohl(chunk->subh.data_hdr->tsn),
1001 chunk->skb ?chunk->skb->head : NULL,
1002 chunk->skb ?
1003 atomic_read(&chunk->skb->users) : -1);
1004
1005 /* Add the chunk to the packet. */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07001006 status = sctp_packet_transmit_chunk(packet, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007
1008 switch (status) {
1009 case SCTP_XMIT_PMTU_FULL:
1010 case SCTP_XMIT_RWND_FULL:
1011 case SCTP_XMIT_NAGLE_DELAY:
1012 /* We could not append this chunk, so put
1013 * the chunk back on the output queue.
1014 */
1015 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
1016 "not transmit TSN: 0x%x, status: %d\n",
1017 ntohl(chunk->subh.data_hdr->tsn),
1018 status);
1019 sctp_outq_head_data(q, chunk);
1020 goto sctp_flush_out;
1021 break;
1022
1023 case SCTP_XMIT_OK:
Wei Yongjunb93d6472009-11-23 15:53:56 -05001024 /* The sender is in the SHUTDOWN-PENDING state,
1025 * The sender MAY set the I-bit in the DATA
1026 * chunk header.
1027 */
1028 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
1029 chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
1030
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 break;
1032
1033 default:
1034 BUG();
1035 }
1036
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001037 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 * call below will succeed all the time and add the
1039 * chunk to the transmitted list and restart the
1040 * timers.
1041 * It is possible that the call can fail under OOM
1042 * conditions.
1043 *
1044 * Is this really a problem? Won't this behave
1045 * like a lost TSN?
1046 */
1047 list_add_tail(&chunk->transmitted_list,
1048 &transport->transmitted);
1049
Vlad Yasevichd9efc222010-04-30 22:41:09 -04001050 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051
1052 q->empty = 0;
1053
1054 /* Only let one DATA chunk get bundled with a
1055 * COOKIE-ECHO chunk.
1056 */
1057 if (packet->has_cookie_echo)
1058 goto sctp_flush_out;
1059 }
1060 break;
1061
1062 default:
1063 /* Do nothing. */
1064 break;
1065 }
1066
1067sctp_flush_out:
1068
1069 /* Before returning, examine all the transports touched in
1070 * this call. Right now, we bluntly force clear all the
1071 * transports. Things might change after we implement Nagle.
1072 * But such an examination is still required.
1073 *
1074 * --xguo
1075 */
1076 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
1077 struct sctp_transport *t = list_entry(ltransport,
1078 struct sctp_transport,
1079 send_ready);
1080 packet = &t->packet;
1081 if (!sctp_packet_empty(packet))
1082 error = sctp_packet_transmit(packet);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001083
1084 /* Clear the burst limited state, if any */
1085 sctp_transport_burst_reset(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086 }
1087
1088 return error;
1089}
1090
1091/* Update unack_data based on the incoming SACK chunk */
1092static void sctp_sack_update_unack_data(struct sctp_association *assoc,
1093 struct sctp_sackhdr *sack)
1094{
1095 sctp_sack_variable_t *frags;
1096 __u16 unack_data;
1097 int i;
1098
1099 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
1100
1101 frags = sack->variable;
1102 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1103 unack_data -= ((ntohs(frags[i].gab.end) -
1104 ntohs(frags[i].gab.start) + 1));
1105 }
1106
1107 assoc->unack_data = unack_data;
1108}
1109
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110/* This is where we REALLY process a SACK.
1111 *
1112 * Process the SACK against the outqueue. Mostly, this just frees
1113 * things off the transmitted queue.
1114 */
1115int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
1116{
1117 struct sctp_association *asoc = q->asoc;
1118 struct sctp_transport *transport;
1119 struct sctp_chunk *tchunk = NULL;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001120 struct list_head *lchunk, *transport_list, *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121 sctp_sack_variable_t *frags = sack->variable;
1122 __u32 sack_ctsn, ctsn, tsn;
1123 __u32 highest_tsn, highest_new_tsn;
1124 __u32 sack_a_rwnd;
1125 unsigned outstanding;
1126 struct sctp_transport *primary = asoc->peer.primary_path;
1127 int count_of_newacks = 0;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001128 int gap_ack_blocks;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001129 u8 accum_moved = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130
1131 /* Grab the association's destination address list. */
1132 transport_list = &asoc->peer.transport_addr_list;
1133
1134 sack_ctsn = ntohl(sack->cum_tsn_ack);
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001135 gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 /*
1137 * SFR-CACC algorithm:
1138 * On receipt of a SACK the sender SHOULD execute the
1139 * following statements.
1140 *
1141 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1142 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1143 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1144 * all destinations.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1146 * is set the receiver of the SACK MUST take the following actions:
1147 *
1148 * A) Initialize the cacc_saw_newack to 0 for all destination
1149 * addresses.
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001150 *
1151 * Only bother if changeover_active is set. Otherwise, this is
1152 * totally suboptimal to do on every SACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 */
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001154 if (primary->cacc.changeover_active) {
1155 u8 clear_cycling = 0;
1156
1157 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1158 primary->cacc.changeover_active = 0;
1159 clear_cycling = 1;
1160 }
1161
1162 if (clear_cycling || gap_ack_blocks) {
1163 list_for_each_entry(transport, transport_list,
1164 transports) {
1165 if (clear_cycling)
1166 transport->cacc.cycling_changeover = 0;
1167 if (gap_ack_blocks)
1168 transport->cacc.cacc_saw_newack = 0;
1169 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 }
1171 }
1172
1173 /* Get the highest TSN in the sack. */
1174 highest_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001175 if (gap_ack_blocks)
1176 highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001178 if (TSN_lt(asoc->highest_sacked, highest_tsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 asoc->highest_sacked = highest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001181 highest_new_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001182
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 /* Run through the retransmit queue. Credit bytes received
1184 * and free those chunks that we can.
1185 */
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001186 sctp_check_transmitted(q, &q->retransmit, NULL, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187
1188 /* Run through the transmitted queue.
1189 * Credit bytes received and free those chunks which we can.
1190 *
1191 * This is a MASSIVE candidate for optimization.
1192 */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001193 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 sctp_check_transmitted(q, &transport->transmitted,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001195 transport, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 /*
1197 * SFR-CACC algorithm:
1198 * C) Let count_of_newacks be the number of
1199 * destinations for which cacc_saw_newack is set.
1200 */
1201 if (transport->cacc.cacc_saw_newack)
1202 count_of_newacks ++;
1203 }
1204
Vlad Yasevichea862c82010-04-30 22:41:10 -04001205 /* Move the Cumulative TSN Ack Point if appropriate. */
1206 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) {
1207 asoc->ctsn_ack_point = sack_ctsn;
1208 accum_moved = 1;
1209 }
1210
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001211 if (gap_ack_blocks) {
Vlad Yasevichea862c82010-04-30 22:41:10 -04001212
1213 if (asoc->fast_recovery && accum_moved)
1214 highest_new_tsn = highest_tsn;
1215
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001216 list_for_each_entry(transport, transport_list, transports)
1217 sctp_mark_missing(q, &transport->transmitted, transport,
1218 highest_new_tsn, count_of_newacks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219 }
1220
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 /* Update unack_data field in the assoc. */
1222 sctp_sack_update_unack_data(asoc, sack);
1223
1224 ctsn = asoc->ctsn_ack_point;
1225
1226 /* Throw away stuff rotting on the sack queue. */
1227 list_for_each_safe(lchunk, temp, &q->sacked) {
1228 tchunk = list_entry(lchunk, struct sctp_chunk,
1229 transmitted_list);
1230 tsn = ntohl(tchunk->subh.data_hdr->tsn);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001231 if (TSN_lte(tsn, ctsn)) {
1232 list_del_init(&tchunk->transmitted_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 sctp_chunk_free(tchunk);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001234 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 }
1236
1237 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1238 * number of bytes still outstanding after processing the
1239 * Cumulative TSN Ack and the Gap Ack Blocks.
1240 */
1241
1242 sack_a_rwnd = ntohl(sack->a_rwnd);
1243 outstanding = q->outstanding_bytes;
1244
1245 if (outstanding < sack_a_rwnd)
1246 sack_a_rwnd -= outstanding;
1247 else
1248 sack_a_rwnd = 0;
1249
1250 asoc->peer.rwnd = sack_a_rwnd;
1251
1252 sctp_generate_fwdtsn(q, sack_ctsn);
1253
1254 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001255 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1257 "%p is 0x%x. Adv peer ack point: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001258 __func__, asoc, ctsn, asoc->adv_peer_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259
1260 /* See if all chunks are acked.
1261 * Make sure the empty queue handler will get run later.
1262 */
David S. Miller79af02c2005-07-08 21:47:49 -07001263 q->empty = (list_empty(&q->out_chunk_list) &&
David S. Miller79af02c2005-07-08 21:47:49 -07001264 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265 if (!q->empty)
1266 goto finish;
1267
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001268 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 q->empty = q->empty && list_empty(&transport->transmitted);
1270 if (!q->empty)
1271 goto finish;
1272 }
1273
1274 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1275finish:
1276 return q->empty;
1277}
1278
1279/* Is the outqueue empty? */
1280int sctp_outq_is_empty(const struct sctp_outq *q)
1281{
1282 return q->empty;
1283}
1284
1285/********************************************************************
1286 * 2nd Level Abstractions
1287 ********************************************************************/
1288
1289/* Go through a transport's transmitted list or the association's retransmit
1290 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1291 * The retransmit list will not have an associated transport.
1292 *
1293 * I added coherent debug information output. --xguo
1294 *
1295 * Instead of printing 'sacked' or 'kept' for each TSN on the
1296 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1297 * KEPT TSN6-TSN7, etc.
1298 */
1299static void sctp_check_transmitted(struct sctp_outq *q,
1300 struct list_head *transmitted_queue,
1301 struct sctp_transport *transport,
1302 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001303 __u32 *highest_new_tsn_in_sack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304{
1305 struct list_head *lchunk;
1306 struct sctp_chunk *tchunk;
1307 struct list_head tlist;
1308 __u32 tsn;
1309 __u32 sack_ctsn;
1310 __u32 rtt;
1311 __u8 restart_timer = 0;
1312 int bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001313 int migrate_bytes = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314
1315 /* These state variables are for coherent debug output. --xguo */
1316
1317#if SCTP_DEBUG
1318 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1319 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1320 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1321 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1322
1323 /* 0 : The last TSN was ACKed.
1324 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1325 * -1: We need to initialize.
1326 */
1327 int dbg_prt_state = -1;
1328#endif /* SCTP_DEBUG */
1329
1330 sack_ctsn = ntohl(sack->cum_tsn_ack);
1331
1332 INIT_LIST_HEAD(&tlist);
1333
1334 /* The while loop will skip empty transmitted queues. */
1335 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1336 tchunk = list_entry(lchunk, struct sctp_chunk,
1337 transmitted_list);
1338
1339 if (sctp_chunk_abandoned(tchunk)) {
1340 /* Move the chunk to abandoned list. */
1341 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001342
1343 /* If this chunk has not been acked, stop
1344 * considering it as 'outstanding'.
1345 */
1346 if (!tchunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001347 if (tchunk->transport)
1348 tchunk->transport->flight_size -=
1349 sctp_data_size(tchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001350 q->outstanding_bytes -= sctp_data_size(tchunk);
1351 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 continue;
1353 }
1354
1355 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1356 if (sctp_acked(sack, tsn)) {
1357 /* If this queue is the retransmit queue, the
1358 * retransmit timer has already reclaimed
1359 * the outstanding bytes for this chunk, so only
1360 * count bytes associated with a transport.
1361 */
1362 if (transport) {
1363 /* If this chunk is being used for RTT
1364 * measurement, calculate the RTT and update
1365 * the RTO using this value.
1366 *
1367 * 6.3.1 C5) Karn's algorithm: RTT measurements
1368 * MUST NOT be made using packets that were
1369 * retransmitted (and thus for which it is
1370 * ambiguous whether the reply was for the
1371 * first instance of the packet or a later
1372 * instance).
1373 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001374 if (!tchunk->tsn_gap_acked &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001376 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 rtt = jiffies - tchunk->sent_at;
1378 sctp_transport_update_rto(transport,
1379 rtt);
1380 }
1381 }
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001382
1383 /* If the chunk hasn't been marked as ACKED,
1384 * mark it and account bytes_acked if the
1385 * chunk had a valid transport (it will not
1386 * have a transport if ASCONF had deleted it
1387 * while DATA was outstanding).
1388 */
1389 if (!tchunk->tsn_gap_acked) {
1390 tchunk->tsn_gap_acked = 1;
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001391 *highest_new_tsn_in_sack = tsn;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001392 bytes_acked += sctp_data_size(tchunk);
1393 if (!tchunk->transport)
1394 migrate_bytes += sctp_data_size(tchunk);
1395 }
1396
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001397 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 /* RFC 2960 6.3.2 Retransmission Timer Rules
1399 *
1400 * R3) Whenever a SACK is received
1401 * that acknowledges the DATA chunk
1402 * with the earliest outstanding TSN
1403 * for that address, restart T3-rtx
1404 * timer for that address with its
1405 * current RTO.
1406 */
1407 restart_timer = 1;
1408
1409 if (!tchunk->tsn_gap_acked) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 /*
1411 * SFR-CACC algorithm:
1412 * 2) If the SACK contains gap acks
1413 * and the flag CHANGEOVER_ACTIVE is
1414 * set the receiver of the SACK MUST
1415 * take the following action:
1416 *
1417 * B) For each TSN t being acked that
1418 * has not been acked in any SACK so
1419 * far, set cacc_saw_newack to 1 for
1420 * the destination that the TSN was
1421 * sent to.
1422 */
1423 if (transport &&
1424 sack->num_gap_ack_blocks &&
1425 q->asoc->peer.primary_path->cacc.
1426 changeover_active)
1427 transport->cacc.cacc_saw_newack
1428 = 1;
1429 }
1430
1431 list_add_tail(&tchunk->transmitted_list,
1432 &q->sacked);
1433 } else {
1434 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1435 * M2) Each time a SACK arrives reporting
1436 * 'Stray DATA chunk(s)' record the highest TSN
1437 * reported as newly acknowledged, call this
1438 * value 'HighestTSNinSack'. A newly
1439 * acknowledged DATA chunk is one not
1440 * previously acknowledged in a SACK.
1441 *
1442 * When the SCTP sender of data receives a SACK
1443 * chunk that acknowledges, for the first time,
1444 * the receipt of a DATA chunk, all the still
1445 * unacknowledged DATA chunks whose TSN is
1446 * older than that newly acknowledged DATA
1447 * chunk, are qualified as 'Stray DATA chunks'.
1448 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 list_add_tail(lchunk, &tlist);
1450 }
1451
1452#if SCTP_DEBUG
1453 switch (dbg_prt_state) {
1454 case 0: /* last TSN was ACKed */
1455 if (dbg_last_ack_tsn + 1 == tsn) {
1456 /* This TSN belongs to the
1457 * current ACK range.
1458 */
1459 break;
1460 }
1461
1462 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1463 /* Display the end of the
1464 * current range.
1465 */
1466 SCTP_DEBUG_PRINTK("-%08x",
1467 dbg_last_ack_tsn);
1468 }
1469
1470 /* Start a new range. */
1471 SCTP_DEBUG_PRINTK(",%08x", tsn);
1472 dbg_ack_tsn = tsn;
1473 break;
1474
1475 case 1: /* The last TSN was NOT ACKed. */
1476 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1477 /* Display the end of current range. */
1478 SCTP_DEBUG_PRINTK("-%08x",
1479 dbg_last_kept_tsn);
1480 }
1481
1482 SCTP_DEBUG_PRINTK("\n");
1483
1484 /* FALL THROUGH... */
1485 default:
1486 /* This is the first-ever TSN we examined. */
1487 /* Start a new range of ACK-ed TSNs. */
1488 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1489 dbg_prt_state = 0;
1490 dbg_ack_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001491 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492
1493 dbg_last_ack_tsn = tsn;
1494#endif /* SCTP_DEBUG */
1495
1496 } else {
1497 if (tchunk->tsn_gap_acked) {
1498 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1499 "data TSN: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001500 __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001501 tsn);
1502 tchunk->tsn_gap_acked = 0;
1503
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001504 if (tchunk->transport)
1505 bytes_acked -= sctp_data_size(tchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506
1507 /* RFC 2960 6.3.2 Retransmission Timer Rules
1508 *
1509 * R4) Whenever a SACK is received missing a
1510 * TSN that was previously acknowledged via a
1511 * Gap Ack Block, start T3-rtx for the
1512 * destination address to which the DATA
1513 * chunk was originally
1514 * transmitted if it is not already running.
1515 */
1516 restart_timer = 1;
1517 }
1518
1519 list_add_tail(lchunk, &tlist);
1520
1521#if SCTP_DEBUG
1522 /* See the above comments on ACK-ed TSNs. */
1523 switch (dbg_prt_state) {
1524 case 1:
1525 if (dbg_last_kept_tsn + 1 == tsn)
1526 break;
1527
1528 if (dbg_last_kept_tsn != dbg_kept_tsn)
1529 SCTP_DEBUG_PRINTK("-%08x",
1530 dbg_last_kept_tsn);
1531
1532 SCTP_DEBUG_PRINTK(",%08x", tsn);
1533 dbg_kept_tsn = tsn;
1534 break;
1535
1536 case 0:
1537 if (dbg_last_ack_tsn != dbg_ack_tsn)
1538 SCTP_DEBUG_PRINTK("-%08x",
1539 dbg_last_ack_tsn);
1540 SCTP_DEBUG_PRINTK("\n");
1541
1542 /* FALL THROUGH... */
1543 default:
1544 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1545 dbg_prt_state = 1;
1546 dbg_kept_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001547 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548
1549 dbg_last_kept_tsn = tsn;
1550#endif /* SCTP_DEBUG */
1551 }
1552 }
1553
1554#if SCTP_DEBUG
1555 /* Finish off the last range, displaying its ending TSN. */
1556 switch (dbg_prt_state) {
1557 case 0:
1558 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1559 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn);
1560 } else {
1561 SCTP_DEBUG_PRINTK("\n");
1562 }
1563 break;
1564
1565 case 1:
1566 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1567 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn);
1568 } else {
1569 SCTP_DEBUG_PRINTK("\n");
1570 }
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001571 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572#endif /* SCTP_DEBUG */
1573 if (transport) {
1574 if (bytes_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001575 /* We may have counted DATA that was migrated
1576 * to this transport due to DEL-IP operation.
1577 * Subtract those bytes, since the were never
1578 * send on this transport and shouldn't be
1579 * credited to this transport.
1580 */
1581 bytes_acked -= migrate_bytes;
1582
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 /* 8.2. When an outstanding TSN is acknowledged,
1584 * the endpoint shall clear the error counter of
1585 * the destination transport address to which the
1586 * DATA chunk was last sent.
1587 * The association's overall error counter is
1588 * also cleared.
1589 */
1590 transport->error_count = 0;
1591 transport->asoc->overall_error_count = 0;
1592
1593 /* Mark the destination transport address as
1594 * active if it is not so marked.
1595 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001596 if ((transport->state == SCTP_INACTIVE) ||
1597 (transport->state == SCTP_UNCONFIRMED)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598 sctp_assoc_control_transport(
1599 transport->asoc,
1600 transport,
1601 SCTP_TRANSPORT_UP,
1602 SCTP_RECEIVED_SACK);
1603 }
1604
1605 sctp_transport_raise_cwnd(transport, sack_ctsn,
1606 bytes_acked);
1607
1608 transport->flight_size -= bytes_acked;
Gui Jianfeng8b73a072008-04-17 14:22:18 -07001609 if (transport->flight_size == 0)
1610 transport->partial_bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001611 q->outstanding_bytes -= bytes_acked + migrate_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 } else {
1613 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1614 * When a sender is doing zero window probing, it
1615 * should not timeout the association if it continues
1616 * to receive new packets from the receiver. The
1617 * reason is that the receiver MAY keep its window
1618 * closed for an indefinite time.
1619 * A sender is doing zero window probing when the
1620 * receiver's advertised window is zero, and there is
1621 * only one data chunk in flight to the receiver.
1622 */
1623 if (!q->asoc->peer.rwnd &&
1624 !list_empty(&tlist) &&
1625 (sack_ctsn+2 == q->asoc->next_tsn)) {
1626 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1627 "window probe: %u\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001628 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 q->asoc->overall_error_count = 0;
1630 transport->error_count = 0;
1631 }
1632 }
1633
1634 /* RFC 2960 6.3.2 Retransmission Timer Rules
1635 *
1636 * R2) Whenever all outstanding data sent to an address have
1637 * been acknowledged, turn off the T3-rtx timer of that
1638 * address.
1639 */
1640 if (!transport->flight_size) {
1641 if (timer_pending(&transport->T3_rtx_timer) &&
1642 del_timer(&transport->T3_rtx_timer)) {
1643 sctp_transport_put(transport);
1644 }
1645 } else if (restart_timer) {
1646 if (!mod_timer(&transport->T3_rtx_timer,
1647 jiffies + transport->rto))
1648 sctp_transport_hold(transport);
1649 }
1650 }
1651
1652 list_splice(&tlist, transmitted_queue);
1653}
1654
1655/* Mark chunks as missing and consequently may get retransmitted. */
1656static void sctp_mark_missing(struct sctp_outq *q,
1657 struct list_head *transmitted_queue,
1658 struct sctp_transport *transport,
1659 __u32 highest_new_tsn_in_sack,
1660 int count_of_newacks)
1661{
1662 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663 __u32 tsn;
1664 char do_fast_retransmit = 0;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001665 struct sctp_association *asoc = q->asoc;
1666 struct sctp_transport *primary = asoc->peer.primary_path;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001668 list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 tsn = ntohl(chunk->subh.data_hdr->tsn);
1671
1672 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1673 * 'Unacknowledged TSN's', if the TSN number of an
1674 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1675 * value, increment the 'TSN.Missing.Report' count on that
1676 * chunk if it has NOT been fast retransmitted or marked for
1677 * fast retransmit already.
1678 */
Neil Hormanc226ef92008-07-25 12:44:09 -04001679 if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001680 !chunk->tsn_gap_acked &&
1681 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1682
1683 /* SFR-CACC may require us to skip marking
1684 * this chunk as missing.
1685 */
1686 if (!transport || !sctp_cacc_skip(primary, transport,
1687 count_of_newacks, tsn)) {
1688 chunk->tsn_missing_report++;
1689
1690 SCTP_DEBUG_PRINTK(
1691 "%s: TSN 0x%x missing counter: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001692 __func__, tsn,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001693 chunk->tsn_missing_report);
1694 }
1695 }
1696 /*
1697 * M4) If any DATA chunk is found to have a
1698 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001699 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001700 * retransmission and start the fast retransmit procedure.
1701 */
1702
Vlad Yasevich27852c22006-02-02 16:57:31 -08001703 if (chunk->tsn_missing_report >= 3) {
Neil Hormanc226ef92008-07-25 12:44:09 -04001704 chunk->fast_retransmit = SCTP_NEED_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705 do_fast_retransmit = 1;
1706 }
1707 }
1708
1709 if (transport) {
1710 if (do_fast_retransmit)
1711 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1712
1713 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1714 "ssthresh: %d, flight_size: %d, pba: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001715 __func__, transport, transport->cwnd,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001716 transport->ssthresh, transport->flight_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 transport->partial_bytes_acked);
1718 }
1719}
1720
1721/* Is the given TSN acked by this packet? */
1722static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1723{
1724 int i;
1725 sctp_sack_variable_t *frags;
1726 __u16 gap;
1727 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1728
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001729 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730 goto pass;
1731
1732 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1733 *
1734 * Gap Ack Blocks:
1735 * These fields contain the Gap Ack Blocks. They are repeated
1736 * for each Gap Ack Block up to the number of Gap Ack Blocks
1737 * defined in the Number of Gap Ack Blocks field. All DATA
1738 * chunks with TSNs greater than or equal to (Cumulative TSN
1739 * Ack + Gap Ack Block Start) and less than or equal to
1740 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1741 * Block are assumed to have been received correctly.
1742 */
1743
1744 frags = sack->variable;
1745 gap = tsn - ctsn;
1746 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1747 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1748 TSN_lte(gap, ntohs(frags[i].gab.end)))
1749 goto pass;
1750 }
1751
1752 return 0;
1753pass:
1754 return 1;
1755}
1756
1757static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001758 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759{
1760 int i;
1761
1762 for (i = 0; i < nskips; i++) {
1763 if (skiplist[i].stream == stream)
1764 return i;
1765 }
1766 return i;
1767}
1768
1769/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1770static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1771{
1772 struct sctp_association *asoc = q->asoc;
1773 struct sctp_chunk *ftsn_chunk = NULL;
1774 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1775 int nskips = 0;
1776 int skip_pos = 0;
1777 __u32 tsn;
1778 struct sctp_chunk *chunk;
1779 struct list_head *lchunk, *temp;
1780
Wei Yongjun76595022009-03-12 09:49:19 +00001781 if (!asoc->peer.prsctp_capable)
1782 return;
1783
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1785 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001786 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1788 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1789 */
1790 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1791 asoc->adv_peer_ack_point = ctsn;
1792
1793 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1794 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1795 * the chunk next in the out-queue space is marked as "abandoned" as
1796 * shown in the following example:
1797 *
1798 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1799 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001800 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1802 * normal SACK processing local advancement
1803 * ... ...
1804 * Adv.Ack.Pt-> 102 acked 102 acked
1805 * 103 abandoned 103 abandoned
1806 * 104 abandoned Adv.Ack.P-> 104 abandoned
1807 * 105 105
1808 * 106 acked 106 acked
1809 * ... ...
1810 *
1811 * In this example, the data sender successfully advanced the
1812 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1813 */
1814 list_for_each_safe(lchunk, temp, &q->abandoned) {
1815 chunk = list_entry(lchunk, struct sctp_chunk,
1816 transmitted_list);
1817 tsn = ntohl(chunk->subh.data_hdr->tsn);
1818
1819 /* Remove any chunks in the abandoned queue that are acked by
1820 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001821 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001822 if (TSN_lte(tsn, ctsn)) {
1823 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001824 sctp_chunk_free(chunk);
1825 } else {
1826 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1827 asoc->adv_peer_ack_point = tsn;
1828 if (chunk->chunk_hdr->flags &
1829 SCTP_DATA_UNORDERED)
1830 continue;
1831 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1832 nskips,
1833 chunk->subh.data_hdr->stream);
1834 ftsn_skip_arr[skip_pos].stream =
1835 chunk->subh.data_hdr->stream;
1836 ftsn_skip_arr[skip_pos].ssn =
1837 chunk->subh.data_hdr->ssn;
1838 if (skip_pos == nskips)
1839 nskips++;
1840 if (nskips == 10)
1841 break;
1842 } else
1843 break;
1844 }
1845 }
1846
1847 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1848 * is greater than the Cumulative TSN ACK carried in the received
1849 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1850 * chunk containing the latest value of the
1851 * "Advanced.Peer.Ack.Point".
1852 *
1853 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1854 * list each stream and sequence number in the forwarded TSN. This
1855 * information will enable the receiver to easily find any
1856 * stranded TSN's waiting on stream reorder queues. Each stream
1857 * SHOULD only be reported once; this means that if multiple
1858 * abandoned messages occur in the same stream then only the
1859 * highest abandoned stream sequence number is reported. If the
1860 * total size of the FORWARD TSN does NOT fit in a single MTU then
1861 * the sender of the FORWARD TSN SHOULD lower the
1862 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1863 * single MTU.
1864 */
1865 if (asoc->adv_peer_ack_point > ctsn)
1866 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001867 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868
1869 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001870 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001871 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1872 }
1873}