blob: fba567a7cb64343dad79285057f0ae8d9a384b98 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (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 *
7 * This file is part of the SCTP kernel reference Implementation
8 *
9 * These functions implement the sctp_outq class. The outqueue handles
10 * bundling and queueing of outgoing SCTP chunks.
11 *
12 * The SCTP reference implementation is free software;
13 * 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 *
18 * The SCTP reference implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Perry Melange <pmelange@null.cc.uic.edu>
40 * Xingang Guo <xingang.guo@intel.com>
41 * Hui Huang <hui.huang@nokia.com>
42 * Sridhar Samudrala <sri@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 *
45 * Any bugs reported given to us we will try to fix... any fixes shared will
46 * be incorporated into the next SCTP release.
47 */
48
49#include <linux/types.h>
50#include <linux/list.h> /* For struct list_head */
51#include <linux/socket.h>
52#include <linux/ip.h>
53#include <net/sock.h> /* For skb_set_owner_w */
54
55#include <net/sctp/sctp.h>
56#include <net/sctp/sm.h>
57
58/* Declare internal functions here. */
59static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
60static void sctp_check_transmitted(struct sctp_outq *q,
61 struct list_head *transmitted_queue,
62 struct sctp_transport *transport,
63 struct sctp_sackhdr *sack,
64 __u32 highest_new_tsn);
65
66static void sctp_mark_missing(struct sctp_outq *q,
67 struct list_head *transmitted_queue,
68 struct sctp_transport *transport,
69 __u32 highest_new_tsn,
70 int count_of_newacks);
71
72static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
73
74/* Add data to the front of the queue. */
75static inline void sctp_outq_head_data(struct sctp_outq *q,
76 struct sctp_chunk *ch)
77{
David S. Miller79af02c2005-07-08 21:47:49 -070078 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 q->out_qlen += ch->skb->len;
80 return;
81}
82
83/* Take data from the front of the queue. */
84static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
85{
David S. Miller79af02c2005-07-08 21:47:49 -070086 struct sctp_chunk *ch = NULL;
87
88 if (!list_empty(&q->out_chunk_list)) {
89 struct list_head *entry = q->out_chunk_list.next;
90
91 ch = list_entry(entry, struct sctp_chunk, list);
92 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 q->out_qlen -= ch->skb->len;
David S. Miller79af02c2005-07-08 21:47:49 -070094 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 return ch;
96}
97/* Add data chunk to the end of the queue. */
98static inline void sctp_outq_tail_data(struct sctp_outq *q,
99 struct sctp_chunk *ch)
100{
David S. Miller79af02c2005-07-08 21:47:49 -0700101 list_add_tail(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 q->out_qlen += ch->skb->len;
103 return;
104}
105
106/*
107 * SFR-CACC algorithm:
108 * D) If count_of_newacks is greater than or equal to 2
109 * and t was not sent to the current primary then the
110 * sender MUST NOT increment missing report count for t.
111 */
112static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
113 struct sctp_transport *transport,
114 int count_of_newacks)
115{
116 if (count_of_newacks >=2 && transport != primary)
117 return 1;
118 return 0;
119}
120
121/*
122 * SFR-CACC algorithm:
123 * F) If count_of_newacks is less than 2, let d be the
124 * destination to which t was sent. If cacc_saw_newack
125 * is 0 for destination d, then the sender MUST NOT
126 * increment missing report count for t.
127 */
128static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
129 int count_of_newacks)
130{
131 if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack)
132 return 1;
133 return 0;
134}
135
136/*
137 * SFR-CACC algorithm:
138 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
139 * execute steps C, D, F.
140 *
141 * C has been implemented in sctp_outq_sack
142 */
143static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
144 struct sctp_transport *transport,
145 int count_of_newacks)
146{
147 if (!primary->cacc.cycling_changeover) {
148 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
149 return 1;
150 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
151 return 1;
152 return 0;
153 }
154 return 0;
155}
156
157/*
158 * SFR-CACC algorithm:
159 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
160 * than next_tsn_at_change of the current primary, then
161 * the sender MUST NOT increment missing report count
162 * for t.
163 */
164static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
165{
166 if (primary->cacc.cycling_changeover &&
167 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
168 return 1;
169 return 0;
170}
171
172/*
173 * SFR-CACC algorithm:
174 * 3) If the missing report count for TSN t is to be
175 * incremented according to [RFC2960] and
176 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
177 * then the sender MUST futher execute steps 3.1 and
178 * 3.2 to determine if the missing report count for
179 * TSN t SHOULD NOT be incremented.
180 *
181 * 3.3) If 3.1 and 3.2 do not dictate that the missing
182 * report count for t should not be incremented, then
183 * the sender SOULD increment missing report count for
184 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
185 */
186static inline int sctp_cacc_skip(struct sctp_transport *primary,
187 struct sctp_transport *transport,
188 int count_of_newacks,
189 __u32 tsn)
190{
191 if (primary->cacc.changeover_active &&
192 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks)
193 || sctp_cacc_skip_3_2(primary, tsn)))
194 return 1;
195 return 0;
196}
197
198/* Initialize an existing sctp_outq. This does the boring stuff.
199 * You still need to define handlers if you really want to DO
200 * something with this structure...
201 */
202void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
203{
204 q->asoc = asoc;
David S. Miller79af02c2005-07-08 21:47:49 -0700205 INIT_LIST_HEAD(&q->out_chunk_list);
206 INIT_LIST_HEAD(&q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 INIT_LIST_HEAD(&q->retransmit);
208 INIT_LIST_HEAD(&q->sacked);
209 INIT_LIST_HEAD(&q->abandoned);
210
211 q->outstanding_bytes = 0;
212 q->empty = 1;
213 q->cork = 0;
214
215 q->malloced = 0;
216 q->out_qlen = 0;
217}
218
219/* Free the outqueue structure and any related pending chunks.
220 */
221void sctp_outq_teardown(struct sctp_outq *q)
222{
223 struct sctp_transport *transport;
224 struct list_head *lchunk, *pos, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700225 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 /* Throw away unacknowledged chunks. */
228 list_for_each(pos, &q->asoc->peer.transport_addr_list) {
229 transport = list_entry(pos, struct sctp_transport, transports);
230 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
231 chunk = list_entry(lchunk, struct sctp_chunk,
232 transmitted_list);
233 /* Mark as part of a failed message. */
234 sctp_chunk_fail(chunk, q->error);
235 sctp_chunk_free(chunk);
236 }
237 }
238
239 /* Throw away chunks that have been gap ACKed. */
240 list_for_each_safe(lchunk, temp, &q->sacked) {
241 list_del_init(lchunk);
242 chunk = list_entry(lchunk, struct sctp_chunk,
243 transmitted_list);
244 sctp_chunk_fail(chunk, q->error);
245 sctp_chunk_free(chunk);
246 }
247
248 /* Throw away any chunks in the retransmit queue. */
249 list_for_each_safe(lchunk, temp, &q->retransmit) {
250 list_del_init(lchunk);
251 chunk = list_entry(lchunk, struct sctp_chunk,
252 transmitted_list);
253 sctp_chunk_fail(chunk, q->error);
254 sctp_chunk_free(chunk);
255 }
256
257 /* Throw away any chunks that are in the abandoned queue. */
258 list_for_each_safe(lchunk, temp, &q->abandoned) {
259 list_del_init(lchunk);
260 chunk = list_entry(lchunk, struct sctp_chunk,
261 transmitted_list);
262 sctp_chunk_fail(chunk, q->error);
263 sctp_chunk_free(chunk);
264 }
265
266 /* Throw away any leftover data chunks. */
267 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
268
269 /* Mark as send failure. */
270 sctp_chunk_fail(chunk, q->error);
271 sctp_chunk_free(chunk);
272 }
273
274 q->error = 0;
275
276 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700277 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
278 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700280 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281}
282
283/* Free the outqueue structure and any related pending chunks. */
284void sctp_outq_free(struct sctp_outq *q)
285{
286 /* Throw away leftover chunks. */
287 sctp_outq_teardown(q);
288
289 /* If we were kmalloc()'d, free the memory. */
290 if (q->malloced)
291 kfree(q);
292}
293
294/* Put a new chunk in an sctp_outq. */
295int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
296{
297 int error = 0;
298
299 SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
300 q, chunk, chunk && chunk->chunk_hdr ?
301 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
302 : "Illegal Chunk");
303
304 /* If it is data, queue it up, otherwise, send it
305 * immediately.
306 */
307 if (SCTP_CID_DATA == chunk->chunk_hdr->type) {
308 /* Is it OK to queue data chunks? */
309 /* From 9. Termination of Association
310 *
311 * When either endpoint performs a shutdown, the
312 * association on each peer will stop accepting new
313 * data from its user and only deliver data in queue
314 * at the time of sending or receiving the SHUTDOWN
315 * chunk.
316 */
317 switch (q->asoc->state) {
318 case SCTP_STATE_EMPTY:
319 case SCTP_STATE_CLOSED:
320 case SCTP_STATE_SHUTDOWN_PENDING:
321 case SCTP_STATE_SHUTDOWN_SENT:
322 case SCTP_STATE_SHUTDOWN_RECEIVED:
323 case SCTP_STATE_SHUTDOWN_ACK_SENT:
324 /* Cannot send after transport endpoint shutdown */
325 error = -ESHUTDOWN;
326 break;
327
328 default:
329 SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
330 q, chunk, chunk && chunk->chunk_hdr ?
331 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
332 : "Illegal Chunk");
333
334 sctp_outq_tail_data(q, chunk);
335 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
336 SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
337 else
338 SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
339 q->empty = 0;
340 break;
341 };
342 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700343 list_add_tail(&chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
345 }
346
347 if (error < 0)
348 return error;
349
350 if (!q->cork)
351 error = sctp_outq_flush(q, 0);
352
353 return error;
354}
355
356/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
357 * and the abandoned list are in ascending order.
358 */
359static void sctp_insert_list(struct list_head *head, struct list_head *new)
360{
361 struct list_head *pos;
362 struct sctp_chunk *nchunk, *lchunk;
363 __u32 ntsn, ltsn;
364 int done = 0;
365
366 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
367 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
368
369 list_for_each(pos, head) {
370 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
371 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
372 if (TSN_lt(ntsn, ltsn)) {
373 list_add(new, pos->prev);
374 done = 1;
375 break;
376 }
377 }
378 if (!done)
379 list_add_tail(new, head);
380}
381
382/* Mark all the eligible packets on a transport for retransmission. */
383void sctp_retransmit_mark(struct sctp_outq *q,
384 struct sctp_transport *transport,
385 __u8 fast_retransmit)
386{
387 struct list_head *lchunk, *ltemp;
388 struct sctp_chunk *chunk;
389
390 /* Walk through the specified transmitted queue. */
391 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
392 chunk = list_entry(lchunk, struct sctp_chunk,
393 transmitted_list);
394
395 /* If the chunk is abandoned, move it to abandoned list. */
396 if (sctp_chunk_abandoned(chunk)) {
397 list_del_init(lchunk);
398 sctp_insert_list(&q->abandoned, lchunk);
399 continue;
400 }
401
402 /* If we are doing retransmission due to a fast retransmit,
403 * only the chunk's that are marked for fast retransmit
404 * should be added to the retransmit queue. If we are doing
405 * retransmission due to a timeout or pmtu discovery, only the
406 * chunks that are not yet acked should be added to the
407 * retransmit queue.
408 */
Vlad Yasevich27852c22006-02-02 16:57:31 -0800409 if ((fast_retransmit && (chunk->fast_retransmit > 0)) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 (!fast_retransmit && !chunk->tsn_gap_acked)) {
411 /* RFC 2960 6.2.1 Processing a Received SACK
412 *
413 * C) Any time a DATA chunk is marked for
414 * retransmission (via either T3-rtx timer expiration
415 * (Section 6.3.3) or via fast retransmit
416 * (Section 7.2.4)), add the data size of those
417 * chunks to the rwnd.
418 */
Sridhar Samudralacd497882006-09-29 17:09:05 -0700419 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
420 sizeof(struct sk_buff));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 q->outstanding_bytes -= sctp_data_size(chunk);
422 transport->flight_size -= sctp_data_size(chunk);
423
424 /* sctpimpguide-05 Section 2.8.2
425 * M5) If a T3-rtx timer expires, the
426 * 'TSN.Missing.Report' of all affected TSNs is set
427 * to 0.
428 */
429 chunk->tsn_missing_report = 0;
430
431 /* If a chunk that is being used for RTT measurement
432 * has to be retransmitted, we cannot use this chunk
433 * anymore for RTT measurements. Reset rto_pending so
434 * that a new RTT measurement is started when a new
435 * data chunk is sent.
436 */
437 if (chunk->rtt_in_progress) {
438 chunk->rtt_in_progress = 0;
439 transport->rto_pending = 0;
440 }
441
442 /* Move the chunk to the retransmit queue. The chunks
443 * on the retransmit queue are always kept in order.
444 */
445 list_del_init(lchunk);
446 sctp_insert_list(&q->retransmit, lchunk);
447 }
448 }
449
450 SCTP_DEBUG_PRINTK("%s: transport: %p, fast_retransmit: %d, "
451 "cwnd: %d, ssthresh: %d, flight_size: %d, "
452 "pba: %d\n", __FUNCTION__,
453 transport, fast_retransmit,
454 transport->cwnd, transport->ssthresh,
455 transport->flight_size,
456 transport->partial_bytes_acked);
457
458}
459
460/* Mark all the eligible packets on a transport for retransmission and force
461 * one packet out.
462 */
463void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
464 sctp_retransmit_reason_t reason)
465{
466 int error = 0;
467 __u8 fast_retransmit = 0;
468
469 switch(reason) {
470 case SCTP_RTXR_T3_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700471 SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
473 /* Update the retran path if the T3-rtx timer has expired for
474 * the current retran path.
475 */
476 if (transport == transport->asoc->peer.retran_path)
477 sctp_assoc_update_retran_path(transport->asoc);
478 break;
479 case SCTP_RTXR_FAST_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700480 SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
482 fast_retransmit = 1;
483 break;
484 case SCTP_RTXR_PMTUD:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700485 SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700487 default:
488 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 }
490
491 sctp_retransmit_mark(q, transport, fast_retransmit);
492
493 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
494 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
495 * following the procedures outlined in C1 - C5.
496 */
497 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
498
499 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
500
501 if (error)
502 q->asoc->base.sk->sk_err = -error;
503}
504
505/*
506 * Transmit DATA chunks on the retransmit queue. Upon return from
507 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
508 * need to be transmitted by the caller.
509 * We assume that pkt->transport has already been set.
510 *
511 * The return value is a normal kernel error return value.
512 */
513static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
514 int rtx_timeout, int *start_timer)
515{
516 struct list_head *lqueue;
517 struct list_head *lchunk, *lchunk1;
518 struct sctp_transport *transport = pkt->transport;
519 sctp_xmit_t status;
520 struct sctp_chunk *chunk, *chunk1;
521 struct sctp_association *asoc;
522 int error = 0;
523
524 asoc = q->asoc;
525 lqueue = &q->retransmit;
526
527 /* RFC 2960 6.3.3 Handle T3-rtx Expiration
528 *
529 * E3) Determine how many of the earliest (i.e., lowest TSN)
530 * outstanding DATA chunks for the address for which the
531 * T3-rtx has expired will fit into a single packet, subject
532 * to the MTU constraint for the path corresponding to the
533 * destination transport address to which the retransmission
534 * is being sent (this may be different from the address for
535 * which the timer expires [see Section 6.4]). Call this value
536 * K. Bundle and retransmit those K DATA chunks in a single
537 * packet to the destination endpoint.
538 *
539 * [Just to be painfully clear, if we are retransmitting
540 * because a timeout just happened, we should send only ONE
541 * packet of retransmitted data.]
542 */
543 lchunk = sctp_list_dequeue(lqueue);
544
545 while (lchunk) {
546 chunk = list_entry(lchunk, struct sctp_chunk,
547 transmitted_list);
548
549 /* Make sure that Gap Acked TSNs are not retransmitted. A
550 * simple approach is just to move such TSNs out of the
551 * way and into a 'transmitted' queue and skip to the
552 * next chunk.
553 */
554 if (chunk->tsn_gap_acked) {
555 list_add_tail(lchunk, &transport->transmitted);
556 lchunk = sctp_list_dequeue(lqueue);
557 continue;
558 }
559
560 /* Attempt to append this chunk to the packet. */
561 status = sctp_packet_append_chunk(pkt, chunk);
562
563 switch (status) {
564 case SCTP_XMIT_PMTU_FULL:
565 /* Send this packet. */
566 if ((error = sctp_packet_transmit(pkt)) == 0)
567 *start_timer = 1;
568
569 /* If we are retransmitting, we should only
570 * send a single packet.
571 */
572 if (rtx_timeout) {
573 list_add(lchunk, lqueue);
574 lchunk = NULL;
575 }
576
577 /* Bundle lchunk in the next round. */
578 break;
579
580 case SCTP_XMIT_RWND_FULL:
581 /* Send this packet. */
582 if ((error = sctp_packet_transmit(pkt)) == 0)
583 *start_timer = 1;
584
585 /* Stop sending DATA as there is no more room
586 * at the receiver.
587 */
588 list_add(lchunk, lqueue);
589 lchunk = NULL;
590 break;
591
592 case SCTP_XMIT_NAGLE_DELAY:
593 /* Send this packet. */
594 if ((error = sctp_packet_transmit(pkt)) == 0)
595 *start_timer = 1;
596
597 /* Stop sending DATA because of nagle delay. */
598 list_add(lchunk, lqueue);
599 lchunk = NULL;
600 break;
601
602 default:
603 /* The append was successful, so add this chunk to
604 * the transmitted list.
605 */
606 list_add_tail(lchunk, &transport->transmitted);
607
608 /* Mark the chunk as ineligible for fast retransmit
609 * after it is retransmitted.
610 */
Vlad Yasevich27852c22006-02-02 16:57:31 -0800611 if (chunk->fast_retransmit > 0)
612 chunk->fast_retransmit = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
614 *start_timer = 1;
615 q->empty = 0;
616
617 /* Retrieve a new chunk to bundle. */
618 lchunk = sctp_list_dequeue(lqueue);
619 break;
620 };
621
622 /* If we are here due to a retransmit timeout or a fast
623 * retransmit and if there are any chunks left in the retransmit
624 * queue that could not fit in the PMTU sized packet, they need * to be marked as ineligible for a subsequent fast retransmit.
625 */
626 if (rtx_timeout && !lchunk) {
627 list_for_each(lchunk1, lqueue) {
628 chunk1 = list_entry(lchunk1, struct sctp_chunk,
629 transmitted_list);
Vlad Yasevich27852c22006-02-02 16:57:31 -0800630 if (chunk1->fast_retransmit > 0)
631 chunk1->fast_retransmit = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 }
633 }
634 }
635
636 return error;
637}
638
639/* Cork the outqueue so queued chunks are really queued. */
640int sctp_outq_uncork(struct sctp_outq *q)
641{
642 int error = 0;
643 if (q->cork) {
644 q->cork = 0;
645 error = sctp_outq_flush(q, 0);
646 }
647 return error;
648}
649
650/*
651 * Try to flush an outqueue.
652 *
653 * Description: Send everything in q which we legally can, subject to
654 * congestion limitations.
655 * * Note: This function can be called from multiple contexts so appropriate
656 * locking concerns must be made. Today we use the sock lock to protect
657 * this function.
658 */
659int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
660{
661 struct sctp_packet *packet;
662 struct sctp_packet singleton;
663 struct sctp_association *asoc = q->asoc;
664 __u16 sport = asoc->base.bind_addr.port;
665 __u16 dport = asoc->peer.port;
666 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 struct sctp_transport *transport = NULL;
668 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700669 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 sctp_xmit_t status;
671 int error = 0;
672 int start_timer = 0;
673
674 /* These transports have chunks to send. */
675 struct list_head transport_list;
676 struct list_head *ltransport;
677
678 INIT_LIST_HEAD(&transport_list);
679 packet = NULL;
680
681 /*
682 * 6.10 Bundling
683 * ...
684 * When bundling control chunks with DATA chunks, an
685 * endpoint MUST place control chunks first in the outbound
686 * SCTP packet. The transmitter MUST transmit DATA chunks
687 * within a SCTP packet in increasing order of TSN.
688 * ...
689 */
690
David S. Miller79af02c2005-07-08 21:47:49 -0700691 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
692 list_del_init(&chunk->list);
693
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 /* Pick the right transport to use. */
695 new_transport = chunk->transport;
696
697 if (!new_transport) {
698 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700699 } else if ((new_transport->state == SCTP_INACTIVE) ||
700 (new_transport->state == SCTP_UNCONFIRMED)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700701 /* If the chunk is Heartbeat or Heartbeat Ack,
702 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 * inactive.
704 *
705 * 3.3.6 Heartbeat Acknowledgement:
706 * ...
707 * A HEARTBEAT ACK is always sent to the source IP
708 * address of the IP datagram containing the
709 * HEARTBEAT chunk to which this ack is responding.
710 * ...
711 */
712 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
713 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK)
714 new_transport = asoc->peer.active_path;
715 }
716
717 /* Are we switching transports?
718 * Take care of transport locks.
719 */
720 if (new_transport != transport) {
721 transport = new_transport;
722 if (list_empty(&transport->send_ready)) {
723 list_add_tail(&transport->send_ready,
724 &transport_list);
725 }
726 packet = &transport->packet;
727 sctp_packet_config(packet, vtag,
728 asoc->peer.ecn_capable);
729 }
730
731 switch (chunk->chunk_hdr->type) {
732 /*
733 * 6.10 Bundling
734 * ...
735 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
736 * COMPLETE with any other chunks. [Send them immediately.]
737 */
738 case SCTP_CID_INIT:
739 case SCTP_CID_INIT_ACK:
740 case SCTP_CID_SHUTDOWN_COMPLETE:
741 sctp_packet_init(&singleton, transport, sport, dport);
742 sctp_packet_config(&singleton, vtag, 0);
743 sctp_packet_append_chunk(&singleton, chunk);
744 error = sctp_packet_transmit(&singleton);
745 if (error < 0)
746 return error;
747 break;
748
749 case SCTP_CID_ABORT:
750 case SCTP_CID_SACK:
751 case SCTP_CID_HEARTBEAT:
752 case SCTP_CID_HEARTBEAT_ACK:
753 case SCTP_CID_SHUTDOWN:
754 case SCTP_CID_SHUTDOWN_ACK:
755 case SCTP_CID_ERROR:
756 case SCTP_CID_COOKIE_ECHO:
757 case SCTP_CID_COOKIE_ACK:
758 case SCTP_CID_ECN_ECNE:
759 case SCTP_CID_ECN_CWR:
760 case SCTP_CID_ASCONF:
761 case SCTP_CID_ASCONF_ACK:
762 case SCTP_CID_FWD_TSN:
763 sctp_packet_transmit_chunk(packet, chunk);
764 break;
765
766 default:
767 /* We built a chunk with an illegal type! */
768 BUG();
769 };
770 }
771
772 /* Is it OK to send data chunks? */
773 switch (asoc->state) {
774 case SCTP_STATE_COOKIE_ECHOED:
775 /* Only allow bundling when this packet has a COOKIE-ECHO
776 * chunk.
777 */
778 if (!packet || !packet->has_cookie_echo)
779 break;
780
781 /* fallthru */
782 case SCTP_STATE_ESTABLISHED:
783 case SCTP_STATE_SHUTDOWN_PENDING:
784 case SCTP_STATE_SHUTDOWN_RECEIVED:
785 /*
786 * RFC 2960 6.1 Transmission of DATA Chunks
787 *
788 * C) When the time comes for the sender to transmit,
789 * before sending new DATA chunks, the sender MUST
790 * first transmit any outstanding DATA chunks which
791 * are marked for retransmission (limited by the
792 * current cwnd).
793 */
794 if (!list_empty(&q->retransmit)) {
795 if (transport == asoc->peer.retran_path)
796 goto retran;
797
798 /* Switch transports & prepare the packet. */
799
800 transport = asoc->peer.retran_path;
801
802 if (list_empty(&transport->send_ready)) {
803 list_add_tail(&transport->send_ready,
804 &transport_list);
805 }
806
807 packet = &transport->packet;
808 sctp_packet_config(packet, vtag,
809 asoc->peer.ecn_capable);
810 retran:
811 error = sctp_outq_flush_rtx(q, packet,
812 rtx_timeout, &start_timer);
813
814 if (start_timer)
815 sctp_transport_reset_timers(transport);
816
817 /* This can happen on COOKIE-ECHO resend. Only
818 * one chunk can get bundled with a COOKIE-ECHO.
819 */
820 if (packet->has_cookie_echo)
821 goto sctp_flush_out;
822
823 /* Don't send new data if there is still data
824 * waiting to retransmit.
825 */
826 if (!list_empty(&q->retransmit))
827 goto sctp_flush_out;
828 }
829
830 /* Finally, transmit new packets. */
831 start_timer = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
833 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
834 * stream identifier.
835 */
836 if (chunk->sinfo.sinfo_stream >=
837 asoc->c.sinit_num_ostreams) {
838
839 /* Mark as failed send. */
840 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
841 sctp_chunk_free(chunk);
842 continue;
843 }
844
845 /* Has this chunk expired? */
846 if (sctp_chunk_abandoned(chunk)) {
847 sctp_chunk_fail(chunk, 0);
848 sctp_chunk_free(chunk);
849 continue;
850 }
851
852 /* If there is a specified transport, use it.
853 * Otherwise, we want to use the active path.
854 */
855 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700856 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700857 ((new_transport->state == SCTP_INACTIVE) ||
858 (new_transport->state == SCTP_UNCONFIRMED)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 new_transport = asoc->peer.active_path;
860
861 /* Change packets if necessary. */
862 if (new_transport != transport) {
863 transport = new_transport;
864
865 /* Schedule to have this transport's
866 * packet flushed.
867 */
868 if (list_empty(&transport->send_ready)) {
869 list_add_tail(&transport->send_ready,
870 &transport_list);
871 }
872
873 packet = &transport->packet;
874 sctp_packet_config(packet, vtag,
875 asoc->peer.ecn_capable);
876 }
877
878 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
879 q, chunk,
880 chunk && chunk->chunk_hdr ?
881 sctp_cname(SCTP_ST_CHUNK(
882 chunk->chunk_hdr->type))
883 : "Illegal Chunk");
884
885 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
886 "%p skb->users %d.\n",
887 ntohl(chunk->subh.data_hdr->tsn),
888 chunk->skb ?chunk->skb->head : NULL,
889 chunk->skb ?
890 atomic_read(&chunk->skb->users) : -1);
891
892 /* Add the chunk to the packet. */
893 status = sctp_packet_transmit_chunk(packet, chunk);
894
895 switch (status) {
896 case SCTP_XMIT_PMTU_FULL:
897 case SCTP_XMIT_RWND_FULL:
898 case SCTP_XMIT_NAGLE_DELAY:
899 /* We could not append this chunk, so put
900 * the chunk back on the output queue.
901 */
902 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
903 "not transmit TSN: 0x%x, status: %d\n",
904 ntohl(chunk->subh.data_hdr->tsn),
905 status);
906 sctp_outq_head_data(q, chunk);
907 goto sctp_flush_out;
908 break;
909
910 case SCTP_XMIT_OK:
911 break;
912
913 default:
914 BUG();
915 }
916
917 /* BUG: We assume that the sctp_packet_transmit()
918 * call below will succeed all the time and add the
919 * chunk to the transmitted list and restart the
920 * timers.
921 * It is possible that the call can fail under OOM
922 * conditions.
923 *
924 * Is this really a problem? Won't this behave
925 * like a lost TSN?
926 */
927 list_add_tail(&chunk->transmitted_list,
928 &transport->transmitted);
929
930 sctp_transport_reset_timers(transport);
931
932 q->empty = 0;
933
934 /* Only let one DATA chunk get bundled with a
935 * COOKIE-ECHO chunk.
936 */
937 if (packet->has_cookie_echo)
938 goto sctp_flush_out;
939 }
940 break;
941
942 default:
943 /* Do nothing. */
944 break;
945 }
946
947sctp_flush_out:
948
949 /* Before returning, examine all the transports touched in
950 * this call. Right now, we bluntly force clear all the
951 * transports. Things might change after we implement Nagle.
952 * But such an examination is still required.
953 *
954 * --xguo
955 */
956 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
957 struct sctp_transport *t = list_entry(ltransport,
958 struct sctp_transport,
959 send_ready);
960 packet = &t->packet;
961 if (!sctp_packet_empty(packet))
962 error = sctp_packet_transmit(packet);
963 }
964
965 return error;
966}
967
968/* Update unack_data based on the incoming SACK chunk */
969static void sctp_sack_update_unack_data(struct sctp_association *assoc,
970 struct sctp_sackhdr *sack)
971{
972 sctp_sack_variable_t *frags;
973 __u16 unack_data;
974 int i;
975
976 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
977
978 frags = sack->variable;
979 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
980 unack_data -= ((ntohs(frags[i].gab.end) -
981 ntohs(frags[i].gab.start) + 1));
982 }
983
984 assoc->unack_data = unack_data;
985}
986
987/* Return the highest new tsn that is acknowledged by the given SACK chunk. */
988static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack,
989 struct sctp_association *asoc)
990{
991 struct list_head *ltransport, *lchunk;
992 struct sctp_transport *transport;
993 struct sctp_chunk *chunk;
994 __u32 highest_new_tsn, tsn;
995 struct list_head *transport_list = &asoc->peer.transport_addr_list;
996
997 highest_new_tsn = ntohl(sack->cum_tsn_ack);
998
999 list_for_each(ltransport, transport_list) {
1000 transport = list_entry(ltransport, struct sctp_transport,
1001 transports);
1002 list_for_each(lchunk, &transport->transmitted) {
1003 chunk = list_entry(lchunk, struct sctp_chunk,
1004 transmitted_list);
1005 tsn = ntohl(chunk->subh.data_hdr->tsn);
1006
1007 if (!chunk->tsn_gap_acked &&
1008 TSN_lt(highest_new_tsn, tsn) &&
1009 sctp_acked(sack, tsn))
1010 highest_new_tsn = tsn;
1011 }
1012 }
1013
1014 return highest_new_tsn;
1015}
1016
1017/* This is where we REALLY process a SACK.
1018 *
1019 * Process the SACK against the outqueue. Mostly, this just frees
1020 * things off the transmitted queue.
1021 */
1022int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
1023{
1024 struct sctp_association *asoc = q->asoc;
1025 struct sctp_transport *transport;
1026 struct sctp_chunk *tchunk = NULL;
1027 struct list_head *lchunk, *transport_list, *pos, *temp;
1028 sctp_sack_variable_t *frags = sack->variable;
1029 __u32 sack_ctsn, ctsn, tsn;
1030 __u32 highest_tsn, highest_new_tsn;
1031 __u32 sack_a_rwnd;
1032 unsigned outstanding;
1033 struct sctp_transport *primary = asoc->peer.primary_path;
1034 int count_of_newacks = 0;
1035
1036 /* Grab the association's destination address list. */
1037 transport_list = &asoc->peer.transport_addr_list;
1038
1039 sack_ctsn = ntohl(sack->cum_tsn_ack);
1040
1041 /*
1042 * SFR-CACC algorithm:
1043 * On receipt of a SACK the sender SHOULD execute the
1044 * following statements.
1045 *
1046 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1047 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1048 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1049 * all destinations.
1050 */
1051 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1052 primary->cacc.changeover_active = 0;
1053 list_for_each(pos, transport_list) {
1054 transport = list_entry(pos, struct sctp_transport,
1055 transports);
1056 transport->cacc.cycling_changeover = 0;
1057 }
1058 }
1059
1060 /*
1061 * SFR-CACC algorithm:
1062 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1063 * is set the receiver of the SACK MUST take the following actions:
1064 *
1065 * A) Initialize the cacc_saw_newack to 0 for all destination
1066 * addresses.
1067 */
Al Viro34bcca22006-11-20 17:27:15 -08001068 if (sack->num_gap_ack_blocks &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069 primary->cacc.changeover_active) {
1070 list_for_each(pos, transport_list) {
1071 transport = list_entry(pos, struct sctp_transport,
1072 transports);
1073 transport->cacc.cacc_saw_newack = 0;
1074 }
1075 }
1076
1077 /* Get the highest TSN in the sack. */
1078 highest_tsn = sack_ctsn;
1079 if (sack->num_gap_ack_blocks)
1080 highest_tsn +=
1081 ntohs(frags[ntohs(sack->num_gap_ack_blocks) - 1].gab.end);
1082
1083 if (TSN_lt(asoc->highest_sacked, highest_tsn)) {
1084 highest_new_tsn = highest_tsn;
1085 asoc->highest_sacked = highest_tsn;
1086 } else {
1087 highest_new_tsn = sctp_highest_new_tsn(sack, asoc);
1088 }
1089
1090 /* Run through the retransmit queue. Credit bytes received
1091 * and free those chunks that we can.
1092 */
1093 sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn);
1094 sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0);
1095
1096 /* Run through the transmitted queue.
1097 * Credit bytes received and free those chunks which we can.
1098 *
1099 * This is a MASSIVE candidate for optimization.
1100 */
1101 list_for_each(pos, transport_list) {
1102 transport = list_entry(pos, struct sctp_transport,
1103 transports);
1104 sctp_check_transmitted(q, &transport->transmitted,
1105 transport, sack, highest_new_tsn);
1106 /*
1107 * SFR-CACC algorithm:
1108 * C) Let count_of_newacks be the number of
1109 * destinations for which cacc_saw_newack is set.
1110 */
1111 if (transport->cacc.cacc_saw_newack)
1112 count_of_newacks ++;
1113 }
1114
1115 list_for_each(pos, transport_list) {
1116 transport = list_entry(pos, struct sctp_transport,
1117 transports);
1118 sctp_mark_missing(q, &transport->transmitted, transport,
1119 highest_new_tsn, count_of_newacks);
1120 }
1121
1122 /* Move the Cumulative TSN Ack Point if appropriate. */
1123 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn))
1124 asoc->ctsn_ack_point = sack_ctsn;
1125
1126 /* Update unack_data field in the assoc. */
1127 sctp_sack_update_unack_data(asoc, sack);
1128
1129 ctsn = asoc->ctsn_ack_point;
1130
1131 /* Throw away stuff rotting on the sack queue. */
1132 list_for_each_safe(lchunk, temp, &q->sacked) {
1133 tchunk = list_entry(lchunk, struct sctp_chunk,
1134 transmitted_list);
1135 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1136 if (TSN_lte(tsn, ctsn))
1137 sctp_chunk_free(tchunk);
1138 }
1139
1140 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1141 * number of bytes still outstanding after processing the
1142 * Cumulative TSN Ack and the Gap Ack Blocks.
1143 */
1144
1145 sack_a_rwnd = ntohl(sack->a_rwnd);
1146 outstanding = q->outstanding_bytes;
1147
1148 if (outstanding < sack_a_rwnd)
1149 sack_a_rwnd -= outstanding;
1150 else
1151 sack_a_rwnd = 0;
1152
1153 asoc->peer.rwnd = sack_a_rwnd;
1154
1155 sctp_generate_fwdtsn(q, sack_ctsn);
1156
1157 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
1158 __FUNCTION__, sack_ctsn);
1159 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1160 "%p is 0x%x. Adv peer ack point: 0x%x\n",
1161 __FUNCTION__, asoc, ctsn, asoc->adv_peer_ack_point);
1162
1163 /* See if all chunks are acked.
1164 * Make sure the empty queue handler will get run later.
1165 */
David S. Miller79af02c2005-07-08 21:47:49 -07001166 q->empty = (list_empty(&q->out_chunk_list) &&
1167 list_empty(&q->control_chunk_list) &&
1168 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 if (!q->empty)
1170 goto finish;
1171
1172 list_for_each(pos, transport_list) {
1173 transport = list_entry(pos, struct sctp_transport,
1174 transports);
1175 q->empty = q->empty && list_empty(&transport->transmitted);
1176 if (!q->empty)
1177 goto finish;
1178 }
1179
1180 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1181finish:
1182 return q->empty;
1183}
1184
1185/* Is the outqueue empty? */
1186int sctp_outq_is_empty(const struct sctp_outq *q)
1187{
1188 return q->empty;
1189}
1190
1191/********************************************************************
1192 * 2nd Level Abstractions
1193 ********************************************************************/
1194
1195/* Go through a transport's transmitted list or the association's retransmit
1196 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1197 * The retransmit list will not have an associated transport.
1198 *
1199 * I added coherent debug information output. --xguo
1200 *
1201 * Instead of printing 'sacked' or 'kept' for each TSN on the
1202 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1203 * KEPT TSN6-TSN7, etc.
1204 */
1205static void sctp_check_transmitted(struct sctp_outq *q,
1206 struct list_head *transmitted_queue,
1207 struct sctp_transport *transport,
1208 struct sctp_sackhdr *sack,
1209 __u32 highest_new_tsn_in_sack)
1210{
1211 struct list_head *lchunk;
1212 struct sctp_chunk *tchunk;
1213 struct list_head tlist;
1214 __u32 tsn;
1215 __u32 sack_ctsn;
1216 __u32 rtt;
1217 __u8 restart_timer = 0;
1218 int bytes_acked = 0;
1219
1220 /* These state variables are for coherent debug output. --xguo */
1221
1222#if SCTP_DEBUG
1223 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1224 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1225 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1226 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1227
1228 /* 0 : The last TSN was ACKed.
1229 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1230 * -1: We need to initialize.
1231 */
1232 int dbg_prt_state = -1;
1233#endif /* SCTP_DEBUG */
1234
1235 sack_ctsn = ntohl(sack->cum_tsn_ack);
1236
1237 INIT_LIST_HEAD(&tlist);
1238
1239 /* The while loop will skip empty transmitted queues. */
1240 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1241 tchunk = list_entry(lchunk, struct sctp_chunk,
1242 transmitted_list);
1243
1244 if (sctp_chunk_abandoned(tchunk)) {
1245 /* Move the chunk to abandoned list. */
1246 sctp_insert_list(&q->abandoned, lchunk);
1247 continue;
1248 }
1249
1250 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1251 if (sctp_acked(sack, tsn)) {
1252 /* If this queue is the retransmit queue, the
1253 * retransmit timer has already reclaimed
1254 * the outstanding bytes for this chunk, so only
1255 * count bytes associated with a transport.
1256 */
1257 if (transport) {
1258 /* If this chunk is being used for RTT
1259 * measurement, calculate the RTT and update
1260 * the RTO using this value.
1261 *
1262 * 6.3.1 C5) Karn's algorithm: RTT measurements
1263 * MUST NOT be made using packets that were
1264 * retransmitted (and thus for which it is
1265 * ambiguous whether the reply was for the
1266 * first instance of the packet or a later
1267 * instance).
1268 */
1269 if (!tchunk->tsn_gap_acked &&
1270 !tchunk->resent &&
1271 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001272 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273 rtt = jiffies - tchunk->sent_at;
1274 sctp_transport_update_rto(transport,
1275 rtt);
1276 }
1277 }
1278 if (TSN_lte(tsn, sack_ctsn)) {
1279 /* RFC 2960 6.3.2 Retransmission Timer Rules
1280 *
1281 * R3) Whenever a SACK is received
1282 * that acknowledges the DATA chunk
1283 * with the earliest outstanding TSN
1284 * for that address, restart T3-rtx
1285 * timer for that address with its
1286 * current RTO.
1287 */
1288 restart_timer = 1;
1289
1290 if (!tchunk->tsn_gap_acked) {
1291 tchunk->tsn_gap_acked = 1;
1292 bytes_acked += sctp_data_size(tchunk);
1293 /*
1294 * SFR-CACC algorithm:
1295 * 2) If the SACK contains gap acks
1296 * and the flag CHANGEOVER_ACTIVE is
1297 * set the receiver of the SACK MUST
1298 * take the following action:
1299 *
1300 * B) For each TSN t being acked that
1301 * has not been acked in any SACK so
1302 * far, set cacc_saw_newack to 1 for
1303 * the destination that the TSN was
1304 * sent to.
1305 */
1306 if (transport &&
1307 sack->num_gap_ack_blocks &&
1308 q->asoc->peer.primary_path->cacc.
1309 changeover_active)
1310 transport->cacc.cacc_saw_newack
1311 = 1;
1312 }
1313
1314 list_add_tail(&tchunk->transmitted_list,
1315 &q->sacked);
1316 } else {
1317 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1318 * M2) Each time a SACK arrives reporting
1319 * 'Stray DATA chunk(s)' record the highest TSN
1320 * reported as newly acknowledged, call this
1321 * value 'HighestTSNinSack'. A newly
1322 * acknowledged DATA chunk is one not
1323 * previously acknowledged in a SACK.
1324 *
1325 * When the SCTP sender of data receives a SACK
1326 * chunk that acknowledges, for the first time,
1327 * the receipt of a DATA chunk, all the still
1328 * unacknowledged DATA chunks whose TSN is
1329 * older than that newly acknowledged DATA
1330 * chunk, are qualified as 'Stray DATA chunks'.
1331 */
1332 if (!tchunk->tsn_gap_acked) {
1333 tchunk->tsn_gap_acked = 1;
1334 bytes_acked += sctp_data_size(tchunk);
1335 }
1336 list_add_tail(lchunk, &tlist);
1337 }
1338
1339#if SCTP_DEBUG
1340 switch (dbg_prt_state) {
1341 case 0: /* last TSN was ACKed */
1342 if (dbg_last_ack_tsn + 1 == tsn) {
1343 /* This TSN belongs to the
1344 * current ACK range.
1345 */
1346 break;
1347 }
1348
1349 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1350 /* Display the end of the
1351 * current range.
1352 */
1353 SCTP_DEBUG_PRINTK("-%08x",
1354 dbg_last_ack_tsn);
1355 }
1356
1357 /* Start a new range. */
1358 SCTP_DEBUG_PRINTK(",%08x", tsn);
1359 dbg_ack_tsn = tsn;
1360 break;
1361
1362 case 1: /* The last TSN was NOT ACKed. */
1363 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1364 /* Display the end of current range. */
1365 SCTP_DEBUG_PRINTK("-%08x",
1366 dbg_last_kept_tsn);
1367 }
1368
1369 SCTP_DEBUG_PRINTK("\n");
1370
1371 /* FALL THROUGH... */
1372 default:
1373 /* This is the first-ever TSN we examined. */
1374 /* Start a new range of ACK-ed TSNs. */
1375 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1376 dbg_prt_state = 0;
1377 dbg_ack_tsn = tsn;
1378 };
1379
1380 dbg_last_ack_tsn = tsn;
1381#endif /* SCTP_DEBUG */
1382
1383 } else {
1384 if (tchunk->tsn_gap_acked) {
1385 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1386 "data TSN: 0x%x\n",
1387 __FUNCTION__,
1388 tsn);
1389 tchunk->tsn_gap_acked = 0;
1390
1391 bytes_acked -= sctp_data_size(tchunk);
1392
1393 /* RFC 2960 6.3.2 Retransmission Timer Rules
1394 *
1395 * R4) Whenever a SACK is received missing a
1396 * TSN that was previously acknowledged via a
1397 * Gap Ack Block, start T3-rtx for the
1398 * destination address to which the DATA
1399 * chunk was originally
1400 * transmitted if it is not already running.
1401 */
1402 restart_timer = 1;
1403 }
1404
1405 list_add_tail(lchunk, &tlist);
1406
1407#if SCTP_DEBUG
1408 /* See the above comments on ACK-ed TSNs. */
1409 switch (dbg_prt_state) {
1410 case 1:
1411 if (dbg_last_kept_tsn + 1 == tsn)
1412 break;
1413
1414 if (dbg_last_kept_tsn != dbg_kept_tsn)
1415 SCTP_DEBUG_PRINTK("-%08x",
1416 dbg_last_kept_tsn);
1417
1418 SCTP_DEBUG_PRINTK(",%08x", tsn);
1419 dbg_kept_tsn = tsn;
1420 break;
1421
1422 case 0:
1423 if (dbg_last_ack_tsn != dbg_ack_tsn)
1424 SCTP_DEBUG_PRINTK("-%08x",
1425 dbg_last_ack_tsn);
1426 SCTP_DEBUG_PRINTK("\n");
1427
1428 /* FALL THROUGH... */
1429 default:
1430 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1431 dbg_prt_state = 1;
1432 dbg_kept_tsn = tsn;
1433 };
1434
1435 dbg_last_kept_tsn = tsn;
1436#endif /* SCTP_DEBUG */
1437 }
1438 }
1439
1440#if SCTP_DEBUG
1441 /* Finish off the last range, displaying its ending TSN. */
1442 switch (dbg_prt_state) {
1443 case 0:
1444 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1445 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn);
1446 } else {
1447 SCTP_DEBUG_PRINTK("\n");
1448 }
1449 break;
1450
1451 case 1:
1452 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1453 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn);
1454 } else {
1455 SCTP_DEBUG_PRINTK("\n");
1456 }
1457 };
1458#endif /* SCTP_DEBUG */
1459 if (transport) {
1460 if (bytes_acked) {
1461 /* 8.2. When an outstanding TSN is acknowledged,
1462 * the endpoint shall clear the error counter of
1463 * the destination transport address to which the
1464 * DATA chunk was last sent.
1465 * The association's overall error counter is
1466 * also cleared.
1467 */
1468 transport->error_count = 0;
1469 transport->asoc->overall_error_count = 0;
1470
1471 /* Mark the destination transport address as
1472 * active if it is not so marked.
1473 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001474 if ((transport->state == SCTP_INACTIVE) ||
1475 (transport->state == SCTP_UNCONFIRMED)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476 sctp_assoc_control_transport(
1477 transport->asoc,
1478 transport,
1479 SCTP_TRANSPORT_UP,
1480 SCTP_RECEIVED_SACK);
1481 }
1482
1483 sctp_transport_raise_cwnd(transport, sack_ctsn,
1484 bytes_acked);
1485
1486 transport->flight_size -= bytes_acked;
1487 q->outstanding_bytes -= bytes_acked;
1488 } else {
1489 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1490 * When a sender is doing zero window probing, it
1491 * should not timeout the association if it continues
1492 * to receive new packets from the receiver. The
1493 * reason is that the receiver MAY keep its window
1494 * closed for an indefinite time.
1495 * A sender is doing zero window probing when the
1496 * receiver's advertised window is zero, and there is
1497 * only one data chunk in flight to the receiver.
1498 */
1499 if (!q->asoc->peer.rwnd &&
1500 !list_empty(&tlist) &&
1501 (sack_ctsn+2 == q->asoc->next_tsn)) {
1502 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1503 "window probe: %u\n",
1504 __FUNCTION__, sack_ctsn);
1505 q->asoc->overall_error_count = 0;
1506 transport->error_count = 0;
1507 }
1508 }
1509
1510 /* RFC 2960 6.3.2 Retransmission Timer Rules
1511 *
1512 * R2) Whenever all outstanding data sent to an address have
1513 * been acknowledged, turn off the T3-rtx timer of that
1514 * address.
1515 */
1516 if (!transport->flight_size) {
1517 if (timer_pending(&transport->T3_rtx_timer) &&
1518 del_timer(&transport->T3_rtx_timer)) {
1519 sctp_transport_put(transport);
1520 }
1521 } else if (restart_timer) {
1522 if (!mod_timer(&transport->T3_rtx_timer,
1523 jiffies + transport->rto))
1524 sctp_transport_hold(transport);
1525 }
1526 }
1527
1528 list_splice(&tlist, transmitted_queue);
1529}
1530
1531/* Mark chunks as missing and consequently may get retransmitted. */
1532static void sctp_mark_missing(struct sctp_outq *q,
1533 struct list_head *transmitted_queue,
1534 struct sctp_transport *transport,
1535 __u32 highest_new_tsn_in_sack,
1536 int count_of_newacks)
1537{
1538 struct sctp_chunk *chunk;
1539 struct list_head *pos;
1540 __u32 tsn;
1541 char do_fast_retransmit = 0;
1542 struct sctp_transport *primary = q->asoc->peer.primary_path;
1543
1544 list_for_each(pos, transmitted_queue) {
1545
1546 chunk = list_entry(pos, struct sctp_chunk, transmitted_list);
1547 tsn = ntohl(chunk->subh.data_hdr->tsn);
1548
1549 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1550 * 'Unacknowledged TSN's', if the TSN number of an
1551 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1552 * value, increment the 'TSN.Missing.Report' count on that
1553 * chunk if it has NOT been fast retransmitted or marked for
1554 * fast retransmit already.
1555 */
1556 if (!chunk->fast_retransmit &&
1557 !chunk->tsn_gap_acked &&
1558 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1559
1560 /* SFR-CACC may require us to skip marking
1561 * this chunk as missing.
1562 */
1563 if (!transport || !sctp_cacc_skip(primary, transport,
1564 count_of_newacks, tsn)) {
1565 chunk->tsn_missing_report++;
1566
1567 SCTP_DEBUG_PRINTK(
1568 "%s: TSN 0x%x missing counter: %d\n",
1569 __FUNCTION__, tsn,
1570 chunk->tsn_missing_report);
1571 }
1572 }
1573 /*
1574 * M4) If any DATA chunk is found to have a
1575 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001576 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001577 * retransmission and start the fast retransmit procedure.
1578 */
1579
Vlad Yasevich27852c22006-02-02 16:57:31 -08001580 if (chunk->tsn_missing_report >= 3) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581 chunk->fast_retransmit = 1;
1582 do_fast_retransmit = 1;
1583 }
1584 }
1585
1586 if (transport) {
1587 if (do_fast_retransmit)
1588 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1589
1590 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1591 "ssthresh: %d, flight_size: %d, pba: %d\n",
1592 __FUNCTION__, transport, transport->cwnd,
1593 transport->ssthresh, transport->flight_size,
1594 transport->partial_bytes_acked);
1595 }
1596}
1597
1598/* Is the given TSN acked by this packet? */
1599static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1600{
1601 int i;
1602 sctp_sack_variable_t *frags;
1603 __u16 gap;
1604 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1605
1606 if (TSN_lte(tsn, ctsn))
1607 goto pass;
1608
1609 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1610 *
1611 * Gap Ack Blocks:
1612 * These fields contain the Gap Ack Blocks. They are repeated
1613 * for each Gap Ack Block up to the number of Gap Ack Blocks
1614 * defined in the Number of Gap Ack Blocks field. All DATA
1615 * chunks with TSNs greater than or equal to (Cumulative TSN
1616 * Ack + Gap Ack Block Start) and less than or equal to
1617 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1618 * Block are assumed to have been received correctly.
1619 */
1620
1621 frags = sack->variable;
1622 gap = tsn - ctsn;
1623 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1624 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1625 TSN_lte(gap, ntohs(frags[i].gab.end)))
1626 goto pass;
1627 }
1628
1629 return 0;
1630pass:
1631 return 1;
1632}
1633
1634static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001635 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636{
1637 int i;
1638
1639 for (i = 0; i < nskips; i++) {
1640 if (skiplist[i].stream == stream)
1641 return i;
1642 }
1643 return i;
1644}
1645
1646/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1647static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1648{
1649 struct sctp_association *asoc = q->asoc;
1650 struct sctp_chunk *ftsn_chunk = NULL;
1651 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1652 int nskips = 0;
1653 int skip_pos = 0;
1654 __u32 tsn;
1655 struct sctp_chunk *chunk;
1656 struct list_head *lchunk, *temp;
1657
1658 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1659 * received SACK.
1660 *
1661 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1662 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1663 */
1664 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1665 asoc->adv_peer_ack_point = ctsn;
1666
1667 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1668 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1669 * the chunk next in the out-queue space is marked as "abandoned" as
1670 * shown in the following example:
1671 *
1672 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1673 * and the Advanced.Peer.Ack.Point is updated to this value:
1674 *
1675 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1676 * normal SACK processing local advancement
1677 * ... ...
1678 * Adv.Ack.Pt-> 102 acked 102 acked
1679 * 103 abandoned 103 abandoned
1680 * 104 abandoned Adv.Ack.P-> 104 abandoned
1681 * 105 105
1682 * 106 acked 106 acked
1683 * ... ...
1684 *
1685 * In this example, the data sender successfully advanced the
1686 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1687 */
1688 list_for_each_safe(lchunk, temp, &q->abandoned) {
1689 chunk = list_entry(lchunk, struct sctp_chunk,
1690 transmitted_list);
1691 tsn = ntohl(chunk->subh.data_hdr->tsn);
1692
1693 /* Remove any chunks in the abandoned queue that are acked by
1694 * the ctsn.
1695 */
1696 if (TSN_lte(tsn, ctsn)) {
1697 list_del_init(lchunk);
1698 if (!chunk->tsn_gap_acked) {
David S. Miller79af02c2005-07-08 21:47:49 -07001699 chunk->transport->flight_size -=
1700 sctp_data_size(chunk);
1701 q->outstanding_bytes -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001702 }
1703 sctp_chunk_free(chunk);
1704 } else {
1705 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1706 asoc->adv_peer_ack_point = tsn;
1707 if (chunk->chunk_hdr->flags &
1708 SCTP_DATA_UNORDERED)
1709 continue;
1710 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1711 nskips,
1712 chunk->subh.data_hdr->stream);
1713 ftsn_skip_arr[skip_pos].stream =
1714 chunk->subh.data_hdr->stream;
1715 ftsn_skip_arr[skip_pos].ssn =
1716 chunk->subh.data_hdr->ssn;
1717 if (skip_pos == nskips)
1718 nskips++;
1719 if (nskips == 10)
1720 break;
1721 } else
1722 break;
1723 }
1724 }
1725
1726 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1727 * is greater than the Cumulative TSN ACK carried in the received
1728 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1729 * chunk containing the latest value of the
1730 * "Advanced.Peer.Ack.Point".
1731 *
1732 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1733 * list each stream and sequence number in the forwarded TSN. This
1734 * information will enable the receiver to easily find any
1735 * stranded TSN's waiting on stream reorder queues. Each stream
1736 * SHOULD only be reported once; this means that if multiple
1737 * abandoned messages occur in the same stream then only the
1738 * highest abandoned stream sequence number is reported. If the
1739 * total size of the FORWARD TSN does NOT fit in a single MTU then
1740 * the sender of the FORWARD TSN SHOULD lower the
1741 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1742 * single MTU.
1743 */
1744 if (asoc->adv_peer_ack_point > ctsn)
1745 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
1746 nskips, &ftsn_skip_arr[0]);
1747
1748 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001749 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1751 }
1752}