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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
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080025 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020030 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Perry Melange <pmelange@null.cc.uic.edu>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Jon Grimm <jgrimm@us.ibm.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 */
41
Joe Perches145ce502010-08-24 13:21:08 +000042#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
43
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <linux/types.h>
45#include <linux/list.h> /* For struct list_head */
46#include <linux/socket.h>
47#include <linux/ip.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090048#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <net/sock.h> /* For skb_set_owner_w */
50
51#include <net/sctp/sctp.h>
52#include <net/sctp/sm.h>
53
54/* Declare internal functions here. */
55static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
56static void sctp_check_transmitted(struct sctp_outq *q,
57 struct list_head *transmitted_queue,
58 struct sctp_transport *transport,
Nicolas Dichteledfee032012-10-03 05:43:22 +000059 union sctp_addr *saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -040061 __u32 *highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63static void sctp_mark_missing(struct sctp_outq *q,
64 struct list_head *transmitted_queue,
65 struct sctp_transport *transport,
66 __u32 highest_new_tsn,
67 int count_of_newacks);
68
69static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
70
Xin Long83dbc3d2016-09-14 02:04:22 +080071static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp);
Adrian Bunkabd0b1982008-07-22 14:20:45 -070072
Linus Torvalds1da177e2005-04-16 15:20:36 -070073/* Add data to the front of the queue. */
74static inline void sctp_outq_head_data(struct sctp_outq *q,
75 struct sctp_chunk *ch)
76{
David S. Miller79af02c2005-07-08 21:47:49 -070077 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079}
80
81/* Take data from the front of the queue. */
82static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
83{
David S. Miller79af02c2005-07-08 21:47:49 -070084 struct sctp_chunk *ch = NULL;
85
86 if (!list_empty(&q->out_chunk_list)) {
87 struct list_head *entry = q->out_chunk_list.next;
88
89 ch = list_entry(entry, struct sctp_chunk, list);
90 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 q->out_qlen -= ch->skb->len;
David S. Miller79af02c2005-07-08 21:47:49 -070092 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 return ch;
94}
95/* Add data chunk to the end of the queue. */
96static inline void sctp_outq_tail_data(struct sctp_outq *q,
97 struct sctp_chunk *ch)
98{
David S. Miller79af02c2005-07-08 21:47:49 -070099 list_add_tail(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101}
102
103/*
104 * SFR-CACC algorithm:
105 * D) If count_of_newacks is greater than or equal to 2
106 * and t was not sent to the current primary then the
107 * sender MUST NOT increment missing report count for t.
108 */
109static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
110 struct sctp_transport *transport,
111 int count_of_newacks)
112{
wangweidongcb3f8372013-12-23 12:16:50 +0800113 if (count_of_newacks >= 2 && transport != primary)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 return 1;
115 return 0;
116}
117
118/*
119 * SFR-CACC algorithm:
120 * F) If count_of_newacks is less than 2, let d be the
121 * destination to which t was sent. If cacc_saw_newack
122 * is 0 for destination d, then the sender MUST NOT
123 * increment missing report count for t.
124 */
125static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
126 int count_of_newacks)
127{
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000128 if (count_of_newacks < 2 &&
129 (transport && !transport->cacc.cacc_saw_newack))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 return 1;
131 return 0;
132}
133
134/*
135 * SFR-CACC algorithm:
136 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
137 * execute steps C, D, F.
138 *
139 * C has been implemented in sctp_outq_sack
140 */
141static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
142 struct sctp_transport *transport,
143 int count_of_newacks)
144{
145 if (!primary->cacc.cycling_changeover) {
146 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
147 return 1;
148 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
149 return 1;
150 return 0;
151 }
152 return 0;
153}
154
155/*
156 * SFR-CACC algorithm:
157 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
158 * than next_tsn_at_change of the current primary, then
159 * the sender MUST NOT increment missing report count
160 * for t.
161 */
162static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
163{
164 if (primary->cacc.cycling_changeover &&
165 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
166 return 1;
167 return 0;
168}
169
170/*
171 * SFR-CACC algorithm:
172 * 3) If the missing report count for TSN t is to be
173 * incremented according to [RFC2960] and
174 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300175 * then the sender MUST further execute steps 3.1 and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 * 3.2 to determine if the missing report count for
177 * TSN t SHOULD NOT be incremented.
178 *
179 * 3.3) If 3.1 and 3.2 do not dictate that the missing
180 * report count for t should not be incremented, then
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300181 * the sender SHOULD increment missing report count for
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
183 */
184static inline int sctp_cacc_skip(struct sctp_transport *primary,
185 struct sctp_transport *transport,
186 int count_of_newacks,
187 __u32 tsn)
188{
189 if (primary->cacc.changeover_active &&
Joe Perchesf64f9e72009-11-29 16:55:45 -0800190 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) ||
191 sctp_cacc_skip_3_2(primary, tsn)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 return 1;
193 return 0;
194}
195
196/* Initialize an existing sctp_outq. This does the boring stuff.
197 * You still need to define handlers if you really want to DO
198 * something with this structure...
199 */
200void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
201{
Neil Hormanc5c77742013-06-12 14:26:44 -0400202 memset(q, 0, sizeof(struct sctp_outq));
203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210}
211
212/* Free the outqueue structure and any related pending chunks.
213 */
Neil Horman2f94aab2013-01-17 11:15:08 +0000214static void __sctp_outq_teardown(struct sctp_outq *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215{
216 struct sctp_transport *transport;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700217 struct list_head *lchunk, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700218 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220 /* Throw away unacknowledged chunks. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700221 list_for_each_entry(transport, &q->asoc->peer.transport_addr_list,
222 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
224 chunk = list_entry(lchunk, struct sctp_chunk,
225 transmitted_list);
226 /* Mark as part of a failed message. */
227 sctp_chunk_fail(chunk, q->error);
228 sctp_chunk_free(chunk);
229 }
230 }
231
232 /* Throw away chunks that have been gap ACKed. */
233 list_for_each_safe(lchunk, temp, &q->sacked) {
234 list_del_init(lchunk);
235 chunk = list_entry(lchunk, struct sctp_chunk,
236 transmitted_list);
237 sctp_chunk_fail(chunk, q->error);
238 sctp_chunk_free(chunk);
239 }
240
241 /* Throw away any chunks in the retransmit queue. */
242 list_for_each_safe(lchunk, temp, &q->retransmit) {
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 that are in the abandoned queue. */
251 list_for_each_safe(lchunk, temp, &q->abandoned) {
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 leftover data chunks. */
260 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
261
262 /* Mark as send failure. */
263 sctp_chunk_fail(chunk, q->error);
264 sctp_chunk_free(chunk);
265 }
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700268 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
269 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700271 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272}
273
Neil Horman2f94aab2013-01-17 11:15:08 +0000274void sctp_outq_teardown(struct sctp_outq *q)
275{
276 __sctp_outq_teardown(q);
277 sctp_outq_init(q->asoc, q);
278}
279
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280/* Free the outqueue structure and any related pending chunks. */
281void sctp_outq_free(struct sctp_outq *q)
282{
283 /* Throw away leftover chunks. */
Neil Horman2f94aab2013-01-17 11:15:08 +0000284 __sctp_outq_teardown(q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285}
286
287/* Put a new chunk in an sctp_outq. */
Xin Long83dbc3d2016-09-14 02:04:22 +0800288void sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000290 struct net *net = sock_net(q->asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
Daniel Borkmannbb333812013-06-28 19:49:40 +0200292 pr_debug("%s: outq:%p, chunk:%p[%s]\n", __func__, q, chunk,
293 chunk && chunk->chunk_hdr ?
294 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) :
295 "illegal chunk");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
297 /* If it is data, queue it up, otherwise, send it
298 * immediately.
299 */
Shan Weiec7b9512010-04-30 22:41:09 -0400300 if (sctp_chunk_is_data(chunk)) {
Xin Long2c897912016-09-14 02:04:18 +0800301 pr_debug("%s: outqueueing: outq:%p, chunk:%p[%s])\n",
302 __func__, q, chunk, chunk && chunk->chunk_hdr ?
303 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) :
304 "illegal chunk");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
Xin Long2c897912016-09-14 02:04:18 +0800306 sctp_outq_tail_data(q, chunk);
David S. Millerb50afd22016-10-02 21:17:07 -0400307 if (chunk->asoc->peer.prsctp_capable &&
Xin Long2c897912016-09-14 02:04:18 +0800308 SCTP_PR_PRIO_ENABLED(chunk->sinfo.sinfo_flags))
309 chunk->asoc->sent_cnt_removable++;
310 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
311 SCTP_INC_STATS(net, SCTP_MIB_OUTUNORDERCHUNKS);
312 else
313 SCTP_INC_STATS(net, SCTP_MIB_OUTORDERCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700315 list_add_tail(&chunk->list, &q->control_chunk_list);
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000316 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 }
318
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 if (!q->cork)
Xin Long83dbc3d2016-09-14 02:04:22 +0800320 sctp_outq_flush(q, 0, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321}
322
323/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
324 * and the abandoned list are in ascending order.
325 */
326static void sctp_insert_list(struct list_head *head, struct list_head *new)
327{
328 struct list_head *pos;
329 struct sctp_chunk *nchunk, *lchunk;
330 __u32 ntsn, ltsn;
331 int done = 0;
332
333 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
334 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
335
336 list_for_each(pos, head) {
337 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
338 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
339 if (TSN_lt(ntsn, ltsn)) {
340 list_add(new, pos->prev);
341 done = 1;
342 break;
343 }
344 }
345 if (!done)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900346 list_add_tail(new, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347}
348
Xin Long8dbdf1f2016-07-09 19:47:45 +0800349static int sctp_prsctp_prune_sent(struct sctp_association *asoc,
350 struct sctp_sndrcvinfo *sinfo,
351 struct list_head *queue, int msg_len)
352{
353 struct sctp_chunk *chk, *temp;
354
355 list_for_each_entry_safe(chk, temp, queue, transmitted_list) {
356 if (!SCTP_PR_PRIO_ENABLED(chk->sinfo.sinfo_flags) ||
Xin Long06054832016-09-29 02:37:27 +0800357 chk->sinfo.sinfo_timetolive <= sinfo->sinfo_timetolive)
Xin Long8dbdf1f2016-07-09 19:47:45 +0800358 continue;
359
360 list_del_init(&chk->transmitted_list);
361 sctp_insert_list(&asoc->outqueue.abandoned,
362 &chk->transmitted_list);
363
364 asoc->sent_cnt_removable--;
365 asoc->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
366
367 if (!chk->tsn_gap_acked) {
368 if (chk->transport)
369 chk->transport->flight_size -=
370 sctp_data_size(chk);
371 asoc->outqueue.outstanding_bytes -= sctp_data_size(chk);
372 }
373
374 msg_len -= SCTP_DATA_SNDSIZE(chk) +
375 sizeof(struct sk_buff) +
376 sizeof(struct sctp_chunk);
377 if (msg_len <= 0)
378 break;
379 }
380
381 return msg_len;
382}
383
384static int sctp_prsctp_prune_unsent(struct sctp_association *asoc,
Xin Long23bb09c2017-03-18 20:03:59 +0800385 struct sctp_sndrcvinfo *sinfo, int msg_len)
Xin Long8dbdf1f2016-07-09 19:47:45 +0800386{
Xin Long23bb09c2017-03-18 20:03:59 +0800387 struct sctp_outq *q = &asoc->outqueue;
Xin Long8dbdf1f2016-07-09 19:47:45 +0800388 struct sctp_chunk *chk, *temp;
389
Xin Long23bb09c2017-03-18 20:03:59 +0800390 list_for_each_entry_safe(chk, temp, &q->out_chunk_list, list) {
Xin Long8dbdf1f2016-07-09 19:47:45 +0800391 if (!SCTP_PR_PRIO_ENABLED(chk->sinfo.sinfo_flags) ||
Xin Long06054832016-09-29 02:37:27 +0800392 chk->sinfo.sinfo_timetolive <= sinfo->sinfo_timetolive)
Xin Long8dbdf1f2016-07-09 19:47:45 +0800393 continue;
394
395 list_del_init(&chk->list);
Xin Long23bb09c2017-03-18 20:03:59 +0800396 q->out_qlen -= chk->skb->len;
Xin Long8dbdf1f2016-07-09 19:47:45 +0800397 asoc->sent_cnt_removable--;
398 asoc->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++;
399
400 msg_len -= SCTP_DATA_SNDSIZE(chk) +
401 sizeof(struct sk_buff) +
402 sizeof(struct sctp_chunk);
403 sctp_chunk_free(chk);
404 if (msg_len <= 0)
405 break;
406 }
407
408 return msg_len;
409}
410
411/* Abandon the chunks according their priorities */
412void sctp_prsctp_prune(struct sctp_association *asoc,
413 struct sctp_sndrcvinfo *sinfo, int msg_len)
414{
415 struct sctp_transport *transport;
416
Xin Longbe4947b2016-09-29 02:37:28 +0800417 if (!asoc->peer.prsctp_capable || !asoc->sent_cnt_removable)
Xin Long8dbdf1f2016-07-09 19:47:45 +0800418 return;
419
420 msg_len = sctp_prsctp_prune_sent(asoc, sinfo,
421 &asoc->outqueue.retransmit,
422 msg_len);
423 if (msg_len <= 0)
424 return;
425
426 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
427 transports) {
428 msg_len = sctp_prsctp_prune_sent(asoc, sinfo,
429 &transport->transmitted,
430 msg_len);
431 if (msg_len <= 0)
432 return;
433 }
434
Xin Long23bb09c2017-03-18 20:03:59 +0800435 sctp_prsctp_prune_unsent(asoc, sinfo, msg_len);
Xin Long8dbdf1f2016-07-09 19:47:45 +0800436}
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438/* Mark all the eligible packets on a transport for retransmission. */
439void sctp_retransmit_mark(struct sctp_outq *q,
440 struct sctp_transport *transport,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400441 __u8 reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442{
443 struct list_head *lchunk, *ltemp;
444 struct sctp_chunk *chunk;
445
446 /* Walk through the specified transmitted queue. */
447 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
448 chunk = list_entry(lchunk, struct sctp_chunk,
449 transmitted_list);
450
451 /* If the chunk is abandoned, move it to abandoned list. */
452 if (sctp_chunk_abandoned(chunk)) {
453 list_del_init(lchunk);
454 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800455
456 /* If this chunk has not been previousely acked,
457 * stop considering it 'outstanding'. Our peer
458 * will most likely never see it since it will
459 * not be retransmitted
460 */
461 if (!chunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400462 if (chunk->transport)
463 chunk->transport->flight_size -=
464 sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800465 q->outstanding_bytes -= sctp_data_size(chunk);
Thomas Grafa76c0ad2011-12-19 04:11:40 +0000466 q->asoc->peer.rwnd += sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800467 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 continue;
469 }
470
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400471 /* If we are doing retransmission due to a timeout or pmtu
472 * discovery, only the chunks that are not yet acked should
473 * be added to the retransmit queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400475 if ((reason == SCTP_RTXR_FAST_RTX &&
Neil Hormanc226ef92008-07-25 12:44:09 -0400476 (chunk->fast_retransmit == SCTP_NEED_FRTX)) ||
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400477 (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 /* RFC 2960 6.2.1 Processing a Received SACK
479 *
480 * C) Any time a DATA chunk is marked for
481 * retransmission (via either T3-rtx timer expiration
482 * (Section 6.3.3) or via fast retransmit
483 * (Section 7.2.4)), add the data size of those
484 * chunks to the rwnd.
485 */
Thomas Grafa76c0ad2011-12-19 04:11:40 +0000486 q->asoc->peer.rwnd += sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 q->outstanding_bytes -= sctp_data_size(chunk);
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400488 if (chunk->transport)
489 transport->flight_size -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
491 /* sctpimpguide-05 Section 2.8.2
492 * M5) If a T3-rtx timer expires, the
493 * 'TSN.Missing.Report' of all affected TSNs is set
494 * to 0.
495 */
496 chunk->tsn_missing_report = 0;
497
498 /* If a chunk that is being used for RTT measurement
499 * has to be retransmitted, we cannot use this chunk
500 * anymore for RTT measurements. Reset rto_pending so
501 * that a new RTT measurement is started when a new
502 * data chunk is sent.
503 */
504 if (chunk->rtt_in_progress) {
505 chunk->rtt_in_progress = 0;
506 transport->rto_pending = 0;
507 }
508
509 /* Move the chunk to the retransmit queue. The chunks
510 * on the retransmit queue are always kept in order.
511 */
512 list_del_init(lchunk);
513 sctp_insert_list(&q->retransmit, lchunk);
514 }
515 }
516
Daniel Borkmannbb333812013-06-28 19:49:40 +0200517 pr_debug("%s: transport:%p, reason:%d, cwnd:%d, ssthresh:%d, "
518 "flight_size:%d, pba:%d\n", __func__, transport, reason,
519 transport->cwnd, transport->ssthresh, transport->flight_size,
520 transport->partial_bytes_acked);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521}
522
523/* Mark all the eligible packets on a transport for retransmission and force
524 * one packet out.
525 */
526void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
527 sctp_retransmit_reason_t reason)
528{
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000529 struct net *net = sock_net(q->asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530
wangweidongcb3f8372013-12-23 12:16:50 +0800531 switch (reason) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 case SCTP_RTXR_T3_RTX:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000533 SCTP_INC_STATS(net, SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
535 /* Update the retran path if the T3-rtx timer has expired for
536 * the current retran path.
537 */
538 if (transport == transport->asoc->peer.retran_path)
539 sctp_assoc_update_retran_path(transport->asoc);
Neil Horman58fbbed2008-02-29 11:40:56 -0800540 transport->asoc->rtx_data_chunks +=
541 transport->asoc->unack_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 break;
543 case SCTP_RTXR_FAST_RTX:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000544 SCTP_INC_STATS(net, SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700546 q->fast_rtx = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 break;
548 case SCTP_RTXR_PMTUD:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000549 SCTP_INC_STATS(net, SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 break;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400551 case SCTP_RTXR_T1_RTX:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000552 SCTP_INC_STATS(net, SCTP_MIB_T1_RETRANSMITS);
Neil Horman58fbbed2008-02-29 11:40:56 -0800553 transport->asoc->init_retries++;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400554 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700555 default:
556 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 }
558
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400559 sctp_retransmit_mark(q, transport, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560
561 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
562 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
563 * following the procedures outlined in C1 - C5.
564 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700565 if (reason == SCTP_RTXR_T3_RTX)
566 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700568 /* Flush the queues only on timeout, since fast_rtx is only
569 * triggered during sack processing and the queue
570 * will be flushed at the end.
571 */
572 if (reason != SCTP_RTXR_FAST_RTX)
Xin Long64519442016-09-14 02:04:21 +0800573 sctp_outq_flush(q, /* rtx_timeout */ 1, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574}
575
576/*
577 * Transmit DATA chunks on the retransmit queue. Upon return from
578 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
579 * need to be transmitted by the caller.
580 * We assume that pkt->transport has already been set.
581 *
582 * The return value is a normal kernel error return value.
583 */
584static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
585 int rtx_timeout, int *start_timer)
586{
587 struct list_head *lqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 struct sctp_transport *transport = pkt->transport;
589 sctp_xmit_t status;
590 struct sctp_chunk *chunk, *chunk1;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700591 int fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 int error = 0;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700593 int timer = 0;
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700594 int done = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 lqueue = &q->retransmit;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700597 fast_rtx = q->fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700599 /* This loop handles time-out retransmissions, fast retransmissions,
600 * and retransmissions due to opening of whindow.
601 *
602 * RFC 2960 6.3.3 Handle T3-rtx Expiration
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 *
604 * E3) Determine how many of the earliest (i.e., lowest TSN)
605 * outstanding DATA chunks for the address for which the
606 * T3-rtx has expired will fit into a single packet, subject
607 * to the MTU constraint for the path corresponding to the
608 * destination transport address to which the retransmission
609 * is being sent (this may be different from the address for
610 * which the timer expires [see Section 6.4]). Call this value
611 * K. Bundle and retransmit those K DATA chunks in a single
612 * packet to the destination endpoint.
613 *
614 * [Just to be painfully clear, if we are retransmitting
615 * because a timeout just happened, we should send only ONE
616 * packet of retransmitted data.]
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700617 *
618 * For fast retransmissions we also send only ONE packet. However,
619 * if we are just flushing the queue due to open window, we'll
620 * try to send as much as possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700622 list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) {
Wei Yongjun4c6a6f42011-04-19 21:32:28 +0000623 /* If the chunk is abandoned, move it to abandoned list. */
624 if (sctp_chunk_abandoned(chunk)) {
625 list_del_init(&chunk->transmitted_list);
626 sctp_insert_list(&q->abandoned,
627 &chunk->transmitted_list);
628 continue;
629 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
631 /* Make sure that Gap Acked TSNs are not retransmitted. A
632 * simple approach is just to move such TSNs out of the
633 * way and into a 'transmitted' queue and skip to the
634 * next chunk.
635 */
636 if (chunk->tsn_gap_acked) {
Wei Yongjun54a27922012-09-03 23:58:16 +0000637 list_move_tail(&chunk->transmitted_list,
638 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 continue;
640 }
641
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700642 /* If we are doing fast retransmit, ignore non-fast_rtransmit
643 * chunks
644 */
645 if (fast_rtx && !chunk->fast_retransmit)
646 continue;
647
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400648redo:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 /* Attempt to append this chunk to the packet. */
650 status = sctp_packet_append_chunk(pkt, chunk);
651
652 switch (status) {
653 case SCTP_XMIT_PMTU_FULL:
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400654 if (!pkt->has_data && !pkt->has_cookie_echo) {
655 /* If this packet did not contain DATA then
656 * retransmission did not happen, so do it
657 * again. We'll ignore the error here since
658 * control chunks are already freed so there
659 * is nothing we can do.
660 */
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -0300661 sctp_packet_transmit(pkt, GFP_ATOMIC);
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400662 goto redo;
663 }
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 /* Send this packet. */
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -0300666 error = sctp_packet_transmit(pkt, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
668 /* If we are retransmitting, we should only
669 * send a single packet.
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000670 * Otherwise, try appending this chunk again.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700672 if (rtx_timeout || fast_rtx)
673 done = 1;
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000674 else
675 goto redo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700677 /* Bundle next chunk in the next round. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 break;
679
680 case SCTP_XMIT_RWND_FULL:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900681 /* Send this packet. */
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -0300682 error = sctp_packet_transmit(pkt, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
684 /* Stop sending DATA as there is no more room
685 * at the receiver.
686 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700687 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 break;
689
David Laight526cbef2014-07-22 08:59:14 +0000690 case SCTP_XMIT_DELAY:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900691 /* Send this packet. */
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -0300692 error = sctp_packet_transmit(pkt, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
694 /* Stop sending DATA because of nagle delay. */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700695 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 break;
697
698 default:
699 /* The append was successful, so add this chunk to
700 * the transmitted list.
701 */
Wei Yongjun54a27922012-09-03 23:58:16 +0000702 list_move_tail(&chunk->transmitted_list,
703 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900705 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 * after it is retransmitted.
707 */
Neil Hormanc226ef92008-07-25 12:44:09 -0400708 if (chunk->fast_retransmit == SCTP_NEED_FRTX)
709 chunk->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710
Michele Baldessari196d6752012-12-01 04:49:42 +0000711 q->asoc->stats.rtxchunks++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700713 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700715 /* Set the timer if there were no errors */
716 if (!error && !timer)
717 timer = 1;
718
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700719 if (done)
720 break;
721 }
722
723 /* If we are here due to a retransmit timeout or a fast
724 * retransmit and if there are any chunks left in the retransmit
725 * queue that could not fit in the PMTU sized packet, they need
726 * to be marked as ineligible for a subsequent fast retransmit.
727 */
728 if (rtx_timeout || fast_rtx) {
729 list_for_each_entry(chunk1, lqueue, transmitted_list) {
Neil Hormanc226ef92008-07-25 12:44:09 -0400730 if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
731 chunk1->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 }
733 }
734
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700735 *start_timer = timer;
736
737 /* Clear fast retransmit hint */
738 if (fast_rtx)
739 q->fast_rtx = 0;
740
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 return error;
742}
743
744/* Cork the outqueue so queued chunks are really queued. */
Xin Long83dbc3d2016-09-14 02:04:22 +0800745void sctp_outq_uncork(struct sctp_outq *q, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746{
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500747 if (q->cork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 q->cork = 0;
Daniel Borkmanndacda322013-04-16 11:07:14 +0000749
Xin Long83dbc3d2016-09-14 02:04:22 +0800750 sctp_outq_flush(q, 0, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751}
752
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754/*
755 * Try to flush an outqueue.
756 *
757 * Description: Send everything in q which we legally can, subject to
758 * congestion limitations.
759 * * Note: This function can be called from multiple contexts so appropriate
760 * locking concerns must be made. Today we use the sock lock to protect
761 * this function.
762 */
Xin Long83dbc3d2016-09-14 02:04:22 +0800763static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764{
765 struct sctp_packet *packet;
766 struct sctp_packet singleton;
767 struct sctp_association *asoc = q->asoc;
768 __u16 sport = asoc->base.bind_addr.port;
769 __u16 dport = asoc->peer.port;
770 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 struct sctp_transport *transport = NULL;
772 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700773 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 sctp_xmit_t status;
775 int error = 0;
776 int start_timer = 0;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700777 int one_packet = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
779 /* These transports have chunks to send. */
780 struct list_head transport_list;
781 struct list_head *ltransport;
782
783 INIT_LIST_HEAD(&transport_list);
784 packet = NULL;
785
786 /*
787 * 6.10 Bundling
788 * ...
789 * When bundling control chunks with DATA chunks, an
790 * endpoint MUST place control chunks first in the outbound
791 * SCTP packet. The transmitter MUST transmit DATA chunks
792 * within a SCTP packet in increasing order of TSN.
793 * ...
794 */
795
David S. Miller79af02c2005-07-08 21:47:49 -0700796 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
Michio Honda8a07eb02011-04-26 20:19:36 +0900797 /* RFC 5061, 5.3
798 * F1) This means that until such time as the ASCONF
799 * containing the add is acknowledged, the sender MUST
800 * NOT use the new IP address as a source for ANY SCTP
801 * packet except on carrying an ASCONF Chunk.
802 */
803 if (asoc->src_out_of_asoc_ok &&
804 chunk->chunk_hdr->type != SCTP_CID_ASCONF)
805 continue;
806
David S. Miller79af02c2005-07-08 21:47:49 -0700807 list_del_init(&chunk->list);
808
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 /* Pick the right transport to use. */
810 new_transport = chunk->transport;
811
812 if (!new_transport) {
Vlad Yasevicha08de642007-12-20 14:11:47 -0800813 /*
814 * If we have a prior transport pointer, see if
815 * the destination address of the chunk
816 * matches the destination address of the
817 * current transport. If not a match, then
818 * try to look up the transport with a given
819 * destination address. We do this because
820 * after processing ASCONFs, we may have new
821 * transports created.
822 */
823 if (transport &&
824 sctp_cmp_addr_exact(&chunk->dest,
825 &transport->ipaddr))
826 new_transport = transport;
827 else
828 new_transport = sctp_assoc_lookup_paddr(asoc,
829 &chunk->dest);
830
831 /* if we still don't have a new transport, then
832 * use the current active path.
833 */
834 if (!new_transport)
835 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700836 } else if ((new_transport->state == SCTP_INACTIVE) ||
Neil Horman5aa93bc2012-07-21 07:56:07 +0000837 (new_transport->state == SCTP_UNCONFIRMED) ||
838 (new_transport->state == SCTP_PF)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700839 /* If the chunk is Heartbeat or Heartbeat Ack,
840 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 * inactive.
842 *
843 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900844 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 * A HEARTBEAT ACK is always sent to the source IP
846 * address of the IP datagram containing the
847 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900848 * ...
Vlad Yasevicha08de642007-12-20 14:11:47 -0800849 *
850 * ASCONF_ACKs also must be sent to the source.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 */
852 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
Vlad Yasevicha08de642007-12-20 14:11:47 -0800853 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
854 chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 new_transport = asoc->peer.active_path;
856 }
857
858 /* Are we switching transports?
859 * Take care of transport locks.
860 */
861 if (new_transport != transport) {
862 transport = new_transport;
863 if (list_empty(&transport->send_ready)) {
864 list_add_tail(&transport->send_ready,
865 &transport_list);
866 }
867 packet = &transport->packet;
868 sctp_packet_config(packet, vtag,
869 asoc->peer.ecn_capable);
870 }
871
872 switch (chunk->chunk_hdr->type) {
873 /*
874 * 6.10 Bundling
875 * ...
876 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
877 * COMPLETE with any other chunks. [Send them immediately.]
878 */
879 case SCTP_CID_INIT:
880 case SCTP_CID_INIT_ACK:
881 case SCTP_CID_SHUTDOWN_COMPLETE:
882 sctp_packet_init(&singleton, transport, sport, dport);
883 sctp_packet_config(&singleton, vtag, 0);
884 sctp_packet_append_chunk(&singleton, chunk);
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -0300885 error = sctp_packet_transmit(&singleton, gfp);
Xin Long64519442016-09-14 02:04:21 +0800886 if (error < 0) {
887 asoc->base.sk->sk_err = -error;
Xin Long83dbc3d2016-09-14 02:04:22 +0800888 return;
Xin Long64519442016-09-14 02:04:21 +0800889 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 break;
891
892 case SCTP_CID_ABORT:
Gui Jianfengf4ad85c2008-04-12 18:39:34 -0700893 if (sctp_test_T_bit(chunk)) {
894 packet->vtag = asoc->c.my_vtag;
895 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700896 /* The following chunks are "response" chunks, i.e.
897 * they are generated in response to something we
898 * received. If we are sending these, then we can
899 * send only 1 packet containing these chunks.
900 */
901 case SCTP_CID_HEARTBEAT_ACK:
902 case SCTP_CID_SHUTDOWN_ACK:
903 case SCTP_CID_COOKIE_ACK:
904 case SCTP_CID_COOKIE_ECHO:
905 case SCTP_CID_ERROR:
906 case SCTP_CID_ECN_CWR:
907 case SCTP_CID_ASCONF_ACK:
908 one_packet = 1;
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300909 /* Fall through */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700910
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 case SCTP_CID_SACK:
912 case SCTP_CID_HEARTBEAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 case SCTP_CID_SHUTDOWN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 case SCTP_CID_ECN_ECNE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 case SCTP_CID_ASCONF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 case SCTP_CID_FWD_TSN:
Xin Long7f9d68a2017-01-18 00:44:47 +0800917 case SCTP_CID_RECONF:
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700918 status = sctp_packet_transmit_chunk(packet, chunk,
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -0300919 one_packet, gfp);
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700920 if (status != SCTP_XMIT_OK) {
921 /* put the chunk back */
922 list_add(&chunk->list, &q->control_chunk_list);
Xin Long7f9d68a2017-01-18 00:44:47 +0800923 break;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700924 }
Xin Long7f9d68a2017-01-18 00:44:47 +0800925
926 asoc->stats.octrlchunks++;
927 /* PR-SCTP C5) If a FORWARD TSN is sent, the
928 * sender MUST assure that at least one T3-rtx
929 * timer is running.
930 */
931 if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
932 sctp_transport_reset_t3_rtx(transport);
933 transport->last_time_sent = jiffies;
934 }
935
936 if (chunk == asoc->strreset_chunk)
937 sctp_transport_reset_reconf_timer(transport);
938
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 break;
940
941 default:
942 /* We built a chunk with an illegal type! */
943 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700944 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 }
946
Michio Honda8a07eb02011-04-26 20:19:36 +0900947 if (q->asoc->src_out_of_asoc_ok)
948 goto sctp_flush_out;
949
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 /* Is it OK to send data chunks? */
951 switch (asoc->state) {
952 case SCTP_STATE_COOKIE_ECHOED:
953 /* Only allow bundling when this packet has a COOKIE-ECHO
954 * chunk.
955 */
956 if (!packet || !packet->has_cookie_echo)
957 break;
958
959 /* fallthru */
960 case SCTP_STATE_ESTABLISHED:
961 case SCTP_STATE_SHUTDOWN_PENDING:
962 case SCTP_STATE_SHUTDOWN_RECEIVED:
963 /*
964 * RFC 2960 6.1 Transmission of DATA Chunks
965 *
966 * C) When the time comes for the sender to transmit,
967 * before sending new DATA chunks, the sender MUST
968 * first transmit any outstanding DATA chunks which
969 * are marked for retransmission (limited by the
970 * current cwnd).
971 */
972 if (!list_empty(&q->retransmit)) {
Michio Hondaf207c052011-06-16 10:54:23 +0900973 if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED)
974 goto sctp_flush_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 if (transport == asoc->peer.retran_path)
976 goto retran;
977
978 /* Switch transports & prepare the packet. */
979
980 transport = asoc->peer.retran_path;
981
982 if (list_empty(&transport->send_ready)) {
983 list_add_tail(&transport->send_ready,
984 &transport_list);
985 }
986
987 packet = &transport->packet;
988 sctp_packet_config(packet, vtag,
989 asoc->peer.ecn_capable);
990 retran:
991 error = sctp_outq_flush_rtx(q, packet,
992 rtx_timeout, &start_timer);
Xin Long64519442016-09-14 02:04:21 +0800993 if (error < 0)
994 asoc->base.sk->sk_err = -error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995
Marcelo Ricardo Leitnerba6f5e32016-04-06 15:15:19 -0300996 if (start_timer) {
997 sctp_transport_reset_t3_rtx(transport);
998 transport->last_time_sent = jiffies;
999 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000
1001 /* This can happen on COOKIE-ECHO resend. Only
1002 * one chunk can get bundled with a COOKIE-ECHO.
1003 */
1004 if (packet->has_cookie_echo)
1005 goto sctp_flush_out;
1006
1007 /* Don't send new data if there is still data
1008 * waiting to retransmit.
1009 */
1010 if (!list_empty(&q->retransmit))
1011 goto sctp_flush_out;
1012 }
1013
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001014 /* Apply Max.Burst limitation to the current transport in
1015 * case it will be used for new data. We are going to
1016 * rest it before we return, but we want to apply the limit
1017 * to the currently queued data.
1018 */
1019 if (transport)
1020 sctp_transport_burst_limited(transport);
1021
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022 /* Finally, transmit new packets. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
Xin Long7f9d68a2017-01-18 00:44:47 +08001024 __u32 sid = ntohs(chunk->subh.data_hdr->stream);
1025
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
1027 * stream identifier.
1028 */
Xin Longafe89962017-03-31 17:57:28 +08001029 if (chunk->sinfo.sinfo_stream >= asoc->stream->outcnt) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030
1031 /* Mark as failed send. */
1032 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
Xin Longbe4947b2016-09-29 02:37:28 +08001033 if (asoc->peer.prsctp_capable &&
Xin Long8dbdf1f2016-07-09 19:47:45 +08001034 SCTP_PR_PRIO_ENABLED(chunk->sinfo.sinfo_flags))
1035 asoc->sent_cnt_removable--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 sctp_chunk_free(chunk);
1037 continue;
1038 }
1039
1040 /* Has this chunk expired? */
1041 if (sctp_chunk_abandoned(chunk)) {
1042 sctp_chunk_fail(chunk, 0);
1043 sctp_chunk_free(chunk);
1044 continue;
1045 }
1046
Xin Long7f9d68a2017-01-18 00:44:47 +08001047 if (asoc->stream->out[sid].state == SCTP_STREAM_CLOSED) {
1048 sctp_outq_head_data(q, chunk);
1049 goto sctp_flush_out;
1050 }
1051
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 /* If there is a specified transport, use it.
1053 * Otherwise, we want to use the active path.
1054 */
1055 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -07001056 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001057 ((new_transport->state == SCTP_INACTIVE) ||
Neil Horman5aa93bc2012-07-21 07:56:07 +00001058 (new_transport->state == SCTP_UNCONFIRMED) ||
1059 (new_transport->state == SCTP_PF)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 new_transport = asoc->peer.active_path;
Marcelo Ricardo Leitner31b055e2016-03-18 18:39:19 -03001061 if (new_transport->state == SCTP_UNCONFIRMED) {
Colin Ian Kingeb004602017-01-10 22:53:06 +00001062 WARN_ONCE(1, "Attempt to send packet on unconfirmed path.");
Marcelo Ricardo Leitner31b055e2016-03-18 18:39:19 -03001063 sctp_chunk_fail(chunk, 0);
1064 sctp_chunk_free(chunk);
Michio Hondaf207c052011-06-16 10:54:23 +09001065 continue;
Marcelo Ricardo Leitner31b055e2016-03-18 18:39:19 -03001066 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067
1068 /* Change packets if necessary. */
1069 if (new_transport != transport) {
1070 transport = new_transport;
1071
1072 /* Schedule to have this transport's
1073 * packet flushed.
1074 */
1075 if (list_empty(&transport->send_ready)) {
1076 list_add_tail(&transport->send_ready,
1077 &transport_list);
1078 }
1079
1080 packet = &transport->packet;
1081 sctp_packet_config(packet, vtag,
1082 asoc->peer.ecn_capable);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001083 /* We've switched transports, so apply the
1084 * Burst limit to the new transport.
1085 */
1086 sctp_transport_burst_limited(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087 }
1088
Daniel Borkmannbb333812013-06-28 19:49:40 +02001089 pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p "
1090 "skb->users:%d\n",
1091 __func__, q, chunk, chunk && chunk->chunk_hdr ?
1092 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) :
1093 "illegal chunk", ntohl(chunk->subh.data_hdr->tsn),
1094 chunk->skb ? chunk->skb->head : NULL, chunk->skb ?
1095 atomic_read(&chunk->skb->users) : -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096
1097 /* Add the chunk to the packet. */
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -03001098 status = sctp_packet_transmit_chunk(packet, chunk, 0, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099
1100 switch (status) {
1101 case SCTP_XMIT_PMTU_FULL:
1102 case SCTP_XMIT_RWND_FULL:
David Laight526cbef2014-07-22 08:59:14 +00001103 case SCTP_XMIT_DELAY:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104 /* We could not append this chunk, so put
1105 * the chunk back on the output queue.
1106 */
Daniel Borkmannbb333812013-06-28 19:49:40 +02001107 pr_debug("%s: could not transmit tsn:0x%x, status:%d\n",
1108 __func__, ntohl(chunk->subh.data_hdr->tsn),
1109 status);
1110
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 sctp_outq_head_data(q, chunk);
1112 goto sctp_flush_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113
1114 case SCTP_XMIT_OK:
Wei Yongjunb93d6472009-11-23 15:53:56 -05001115 /* The sender is in the SHUTDOWN-PENDING state,
1116 * The sender MAY set the I-bit in the DATA
1117 * chunk header.
1118 */
1119 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
1120 chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
Michele Baldessari196d6752012-12-01 04:49:42 +00001121 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
1122 asoc->stats.ouodchunks++;
1123 else
1124 asoc->stats.oodchunks++;
Wei Yongjunb93d6472009-11-23 15:53:56 -05001125
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 break;
1127
1128 default:
1129 BUG();
1130 }
1131
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001132 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 * call below will succeed all the time and add the
1134 * chunk to the transmitted list and restart the
1135 * timers.
1136 * It is possible that the call can fail under OOM
1137 * conditions.
1138 *
1139 * Is this really a problem? Won't this behave
1140 * like a lost TSN?
1141 */
1142 list_add_tail(&chunk->transmitted_list,
1143 &transport->transmitted);
1144
Marcelo Ricardo Leitnerba6f5e32016-04-06 15:15:19 -03001145 sctp_transport_reset_t3_rtx(transport);
1146 transport->last_time_sent = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148 /* Only let one DATA chunk get bundled with a
1149 * COOKIE-ECHO chunk.
1150 */
1151 if (packet->has_cookie_echo)
1152 goto sctp_flush_out;
1153 }
1154 break;
1155
1156 default:
1157 /* Do nothing. */
1158 break;
1159 }
1160
1161sctp_flush_out:
1162
1163 /* Before returning, examine all the transports touched in
1164 * this call. Right now, we bluntly force clear all the
1165 * transports. Things might change after we implement Nagle.
1166 * But such an examination is still required.
1167 *
1168 * --xguo
1169 */
wangweidongcb3f8372013-12-23 12:16:50 +08001170 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171 struct sctp_transport *t = list_entry(ltransport,
1172 struct sctp_transport,
1173 send_ready);
1174 packet = &t->packet;
Xin Long64519442016-09-14 02:04:21 +08001175 if (!sctp_packet_empty(packet)) {
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -03001176 error = sctp_packet_transmit(packet, gfp);
Xin Long64519442016-09-14 02:04:21 +08001177 if (error < 0)
1178 asoc->base.sk->sk_err = -error;
1179 }
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001180
1181 /* Clear the burst limited state, if any */
1182 sctp_transport_burst_reset(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184}
1185
1186/* Update unack_data based on the incoming SACK chunk */
1187static void sctp_sack_update_unack_data(struct sctp_association *assoc,
1188 struct sctp_sackhdr *sack)
1189{
1190 sctp_sack_variable_t *frags;
1191 __u16 unack_data;
1192 int i;
1193
1194 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
1195
1196 frags = sack->variable;
1197 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1198 unack_data -= ((ntohs(frags[i].gab.end) -
1199 ntohs(frags[i].gab.start) + 1));
1200 }
1201
1202 assoc->unack_data = unack_data;
1203}
1204
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205/* This is where we REALLY process a SACK.
1206 *
1207 * Process the SACK against the outqueue. Mostly, this just frees
1208 * things off the transmitted queue.
1209 */
Nicolas Dichteledfee032012-10-03 05:43:22 +00001210int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211{
1212 struct sctp_association *asoc = q->asoc;
Nicolas Dichteledfee032012-10-03 05:43:22 +00001213 struct sctp_sackhdr *sack = chunk->subh.sack_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 struct sctp_transport *transport;
1215 struct sctp_chunk *tchunk = NULL;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001216 struct list_head *lchunk, *transport_list, *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 sctp_sack_variable_t *frags = sack->variable;
1218 __u32 sack_ctsn, ctsn, tsn;
1219 __u32 highest_tsn, highest_new_tsn;
1220 __u32 sack_a_rwnd;
Eric Dumazet95c96172012-04-15 05:58:06 +00001221 unsigned int outstanding;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 struct sctp_transport *primary = asoc->peer.primary_path;
1223 int count_of_newacks = 0;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001224 int gap_ack_blocks;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001225 u8 accum_moved = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226
1227 /* Grab the association's destination address list. */
1228 transport_list = &asoc->peer.transport_addr_list;
1229
1230 sack_ctsn = ntohl(sack->cum_tsn_ack);
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001231 gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
Michele Baldessari196d6752012-12-01 04:49:42 +00001232 asoc->stats.gapcnt += gap_ack_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 /*
1234 * SFR-CACC algorithm:
1235 * On receipt of a SACK the sender SHOULD execute the
1236 * following statements.
1237 *
1238 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1239 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1240 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1241 * all destinations.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1243 * is set the receiver of the SACK MUST take the following actions:
1244 *
1245 * A) Initialize the cacc_saw_newack to 0 for all destination
1246 * addresses.
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001247 *
1248 * Only bother if changeover_active is set. Otherwise, this is
1249 * totally suboptimal to do on every SACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 */
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001251 if (primary->cacc.changeover_active) {
1252 u8 clear_cycling = 0;
1253
1254 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1255 primary->cacc.changeover_active = 0;
1256 clear_cycling = 1;
1257 }
1258
1259 if (clear_cycling || gap_ack_blocks) {
1260 list_for_each_entry(transport, transport_list,
1261 transports) {
1262 if (clear_cycling)
1263 transport->cacc.cycling_changeover = 0;
1264 if (gap_ack_blocks)
1265 transport->cacc.cacc_saw_newack = 0;
1266 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 }
1268 }
1269
1270 /* Get the highest TSN in the sack. */
1271 highest_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001272 if (gap_ack_blocks)
1273 highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001275 if (TSN_lt(asoc->highest_sacked, highest_tsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 asoc->highest_sacked = highest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001278 highest_new_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001279
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 /* Run through the retransmit queue. Credit bytes received
1281 * and free those chunks that we can.
1282 */
Nicolas Dichteledfee032012-10-03 05:43:22 +00001283 sctp_check_transmitted(q, &q->retransmit, NULL, NULL, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284
1285 /* Run through the transmitted queue.
1286 * Credit bytes received and free those chunks which we can.
1287 *
1288 * This is a MASSIVE candidate for optimization.
1289 */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001290 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 sctp_check_transmitted(q, &transport->transmitted,
Nicolas Dichteledfee032012-10-03 05:43:22 +00001292 transport, &chunk->source, sack,
1293 &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 /*
1295 * SFR-CACC algorithm:
1296 * C) Let count_of_newacks be the number of
1297 * destinations for which cacc_saw_newack is set.
1298 */
1299 if (transport->cacc.cacc_saw_newack)
wangweidongcb3f8372013-12-23 12:16:50 +08001300 count_of_newacks++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 }
1302
Vlad Yasevichea862c82010-04-30 22:41:10 -04001303 /* Move the Cumulative TSN Ack Point if appropriate. */
1304 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) {
1305 asoc->ctsn_ack_point = sack_ctsn;
1306 accum_moved = 1;
1307 }
1308
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001309 if (gap_ack_blocks) {
Vlad Yasevichea862c82010-04-30 22:41:10 -04001310
1311 if (asoc->fast_recovery && accum_moved)
1312 highest_new_tsn = highest_tsn;
1313
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001314 list_for_each_entry(transport, transport_list, transports)
1315 sctp_mark_missing(q, &transport->transmitted, transport,
1316 highest_new_tsn, count_of_newacks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 }
1318
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 /* Update unack_data field in the assoc. */
1320 sctp_sack_update_unack_data(asoc, sack);
1321
1322 ctsn = asoc->ctsn_ack_point;
1323
1324 /* Throw away stuff rotting on the sack queue. */
1325 list_for_each_safe(lchunk, temp, &q->sacked) {
1326 tchunk = list_entry(lchunk, struct sctp_chunk,
1327 transmitted_list);
1328 tsn = ntohl(tchunk->subh.data_hdr->tsn);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001329 if (TSN_lte(tsn, ctsn)) {
1330 list_del_init(&tchunk->transmitted_list);
Xin Longbe4947b2016-09-29 02:37:28 +08001331 if (asoc->peer.prsctp_capable &&
Xin Long8dbdf1f2016-07-09 19:47:45 +08001332 SCTP_PR_PRIO_ENABLED(chunk->sinfo.sinfo_flags))
1333 asoc->sent_cnt_removable--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 sctp_chunk_free(tchunk);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001335 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336 }
1337
1338 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1339 * number of bytes still outstanding after processing the
1340 * Cumulative TSN Ack and the Gap Ack Blocks.
1341 */
1342
1343 sack_a_rwnd = ntohl(sack->a_rwnd);
lucien8a0d19c2015-12-05 15:35:36 +08001344 asoc->peer.zero_window_announced = !sack_a_rwnd;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 outstanding = q->outstanding_bytes;
1346
1347 if (outstanding < sack_a_rwnd)
1348 sack_a_rwnd -= outstanding;
1349 else
1350 sack_a_rwnd = 0;
1351
1352 asoc->peer.rwnd = sack_a_rwnd;
1353
1354 sctp_generate_fwdtsn(q, sack_ctsn);
1355
Daniel Borkmannbb333812013-06-28 19:49:40 +02001356 pr_debug("%s: sack cumulative tsn ack:0x%x\n", __func__, sack_ctsn);
1357 pr_debug("%s: cumulative tsn ack of assoc:%p is 0x%x, "
1358 "advertised peer ack point:0x%x\n", __func__, asoc, ctsn,
1359 asoc->adv_peer_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360
Vlad Yasevich619a60e2014-01-02 14:39:44 -05001361 return sctp_outq_is_empty(q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362}
1363
Vlad Yasevich619a60e2014-01-02 14:39:44 -05001364/* Is the outqueue empty?
1365 * The queue is empty when we have not pending data, no in-flight data
1366 * and nothing pending retransmissions.
1367 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368int sctp_outq_is_empty(const struct sctp_outq *q)
1369{
Vlad Yasevich619a60e2014-01-02 14:39:44 -05001370 return q->out_qlen == 0 && q->outstanding_bytes == 0 &&
1371 list_empty(&q->retransmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372}
1373
1374/********************************************************************
1375 * 2nd Level Abstractions
1376 ********************************************************************/
1377
1378/* Go through a transport's transmitted list or the association's retransmit
1379 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1380 * The retransmit list will not have an associated transport.
1381 *
1382 * I added coherent debug information output. --xguo
1383 *
1384 * Instead of printing 'sacked' or 'kept' for each TSN on the
1385 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1386 * KEPT TSN6-TSN7, etc.
1387 */
1388static void sctp_check_transmitted(struct sctp_outq *q,
1389 struct list_head *transmitted_queue,
1390 struct sctp_transport *transport,
Nicolas Dichteledfee032012-10-03 05:43:22 +00001391 union sctp_addr *saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001393 __u32 *highest_new_tsn_in_sack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394{
1395 struct list_head *lchunk;
1396 struct sctp_chunk *tchunk;
1397 struct list_head tlist;
1398 __u32 tsn;
1399 __u32 sack_ctsn;
1400 __u32 rtt;
1401 __u8 restart_timer = 0;
1402 int bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001403 int migrate_bytes = 0;
Daniel Borkmann8c2f4142013-07-09 16:17:04 +02001404 bool forward_progress = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 sack_ctsn = ntohl(sack->cum_tsn_ack);
1407
1408 INIT_LIST_HEAD(&tlist);
1409
1410 /* The while loop will skip empty transmitted queues. */
1411 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1412 tchunk = list_entry(lchunk, struct sctp_chunk,
1413 transmitted_list);
1414
1415 if (sctp_chunk_abandoned(tchunk)) {
1416 /* Move the chunk to abandoned list. */
1417 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001418
1419 /* If this chunk has not been acked, stop
1420 * considering it as 'outstanding'.
1421 */
1422 if (!tchunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001423 if (tchunk->transport)
1424 tchunk->transport->flight_size -=
1425 sctp_data_size(tchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001426 q->outstanding_bytes -= sctp_data_size(tchunk);
1427 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 continue;
1429 }
1430
1431 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1432 if (sctp_acked(sack, tsn)) {
1433 /* If this queue is the retransmit queue, the
1434 * retransmit timer has already reclaimed
1435 * the outstanding bytes for this chunk, so only
1436 * count bytes associated with a transport.
1437 */
1438 if (transport) {
1439 /* If this chunk is being used for RTT
1440 * measurement, calculate the RTT and update
1441 * the RTO using this value.
1442 *
1443 * 6.3.1 C5) Karn's algorithm: RTT measurements
1444 * MUST NOT be made using packets that were
1445 * retransmitted (and thus for which it is
1446 * ambiguous whether the reply was for the
1447 * first instance of the packet or a later
1448 * instance).
1449 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001450 if (!tchunk->tsn_gap_acked &&
Xin Longcc6ac9b2016-10-08 11:36:05 +08001451 !sctp_chunk_retransmitted(tchunk) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001453 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 rtt = jiffies - tchunk->sent_at;
1455 sctp_transport_update_rto(transport,
1456 rtt);
1457 }
1458 }
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001459
1460 /* If the chunk hasn't been marked as ACKED,
1461 * mark it and account bytes_acked if the
1462 * chunk had a valid transport (it will not
1463 * have a transport if ASCONF had deleted it
1464 * while DATA was outstanding).
1465 */
1466 if (!tchunk->tsn_gap_acked) {
1467 tchunk->tsn_gap_acked = 1;
Chang Xiangzhongd6c41612013-11-21 22:56:28 +01001468 if (TSN_lt(*highest_new_tsn_in_sack, tsn))
1469 *highest_new_tsn_in_sack = tsn;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001470 bytes_acked += sctp_data_size(tchunk);
1471 if (!tchunk->transport)
1472 migrate_bytes += sctp_data_size(tchunk);
Daniel Borkmann8c2f4142013-07-09 16:17:04 +02001473 forward_progress = true;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001474 }
1475
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001476 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477 /* RFC 2960 6.3.2 Retransmission Timer Rules
1478 *
1479 * R3) Whenever a SACK is received
1480 * that acknowledges the DATA chunk
1481 * with the earliest outstanding TSN
1482 * for that address, restart T3-rtx
1483 * timer for that address with its
1484 * current RTO.
1485 */
1486 restart_timer = 1;
Daniel Borkmann8c2f4142013-07-09 16:17:04 +02001487 forward_progress = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488
1489 if (!tchunk->tsn_gap_acked) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 /*
1491 * SFR-CACC algorithm:
1492 * 2) If the SACK contains gap acks
1493 * and the flag CHANGEOVER_ACTIVE is
1494 * set the receiver of the SACK MUST
1495 * take the following action:
1496 *
1497 * B) For each TSN t being acked that
1498 * has not been acked in any SACK so
1499 * far, set cacc_saw_newack to 1 for
1500 * the destination that the TSN was
1501 * sent to.
1502 */
1503 if (transport &&
1504 sack->num_gap_ack_blocks &&
1505 q->asoc->peer.primary_path->cacc.
1506 changeover_active)
1507 transport->cacc.cacc_saw_newack
1508 = 1;
1509 }
1510
1511 list_add_tail(&tchunk->transmitted_list,
1512 &q->sacked);
1513 } else {
1514 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1515 * M2) Each time a SACK arrives reporting
1516 * 'Stray DATA chunk(s)' record the highest TSN
1517 * reported as newly acknowledged, call this
1518 * value 'HighestTSNinSack'. A newly
1519 * acknowledged DATA chunk is one not
1520 * previously acknowledged in a SACK.
1521 *
1522 * When the SCTP sender of data receives a SACK
1523 * chunk that acknowledges, for the first time,
1524 * the receipt of a DATA chunk, all the still
1525 * unacknowledged DATA chunks whose TSN is
1526 * older than that newly acknowledged DATA
1527 * chunk, are qualified as 'Stray DATA chunks'.
1528 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529 list_add_tail(lchunk, &tlist);
1530 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531 } else {
1532 if (tchunk->tsn_gap_acked) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02001533 pr_debug("%s: receiver reneged on data TSN:0x%x\n",
1534 __func__, tsn);
1535
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 tchunk->tsn_gap_acked = 0;
1537
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001538 if (tchunk->transport)
1539 bytes_acked -= sctp_data_size(tchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540
1541 /* RFC 2960 6.3.2 Retransmission Timer Rules
1542 *
1543 * R4) Whenever a SACK is received missing a
1544 * TSN that was previously acknowledged via a
1545 * Gap Ack Block, start T3-rtx for the
1546 * destination address to which the DATA
1547 * chunk was originally
1548 * transmitted if it is not already running.
1549 */
1550 restart_timer = 1;
1551 }
1552
1553 list_add_tail(lchunk, &tlist);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554 }
1555 }
1556
Linus Torvalds1da177e2005-04-16 15:20:36 -07001557 if (transport) {
1558 if (bytes_acked) {
Thomas Graff8d96052011-07-07 00:28:35 +00001559 struct sctp_association *asoc = transport->asoc;
1560
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001561 /* We may have counted DATA that was migrated
1562 * to this transport due to DEL-IP operation.
1563 * Subtract those bytes, since the were never
1564 * send on this transport and shouldn't be
1565 * credited to this transport.
1566 */
1567 bytes_acked -= migrate_bytes;
1568
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 /* 8.2. When an outstanding TSN is acknowledged,
1570 * the endpoint shall clear the error counter of
1571 * the destination transport address to which the
1572 * DATA chunk was last sent.
1573 * The association's overall error counter is
1574 * also cleared.
1575 */
1576 transport->error_count = 0;
1577 transport->asoc->overall_error_count = 0;
Daniel Borkmann8c2f4142013-07-09 16:17:04 +02001578 forward_progress = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579
Thomas Graff8d96052011-07-07 00:28:35 +00001580 /*
1581 * While in SHUTDOWN PENDING, we may have started
1582 * the T5 shutdown guard timer after reaching the
1583 * retransmission limit. Stop that timer as soon
1584 * as the receiver acknowledged any data.
1585 */
1586 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING &&
1587 del_timer(&asoc->timers
1588 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]))
1589 sctp_association_put(asoc);
1590
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591 /* Mark the destination transport address as
1592 * active if it is not so marked.
1593 */
Nicolas Dichteledfee032012-10-03 05:43:22 +00001594 if ((transport->state == SCTP_INACTIVE ||
1595 transport->state == SCTP_UNCONFIRMED) &&
1596 sctp_cmp_addr_exact(&transport->ipaddr, saddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 sctp_assoc_control_transport(
1598 transport->asoc,
1599 transport,
1600 SCTP_TRANSPORT_UP,
1601 SCTP_RECEIVED_SACK);
1602 }
1603
1604 sctp_transport_raise_cwnd(transport, sack_ctsn,
1605 bytes_acked);
1606
1607 transport->flight_size -= bytes_acked;
Gui Jianfeng8b73a072008-04-17 14:22:18 -07001608 if (transport->flight_size == 0)
1609 transport->partial_bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001610 q->outstanding_bytes -= bytes_acked + migrate_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611 } else {
1612 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1613 * When a sender is doing zero window probing, it
1614 * should not timeout the association if it continues
1615 * to receive new packets from the receiver. The
1616 * reason is that the receiver MAY keep its window
1617 * closed for an indefinite time.
1618 * A sender is doing zero window probing when the
1619 * receiver's advertised window is zero, and there is
1620 * only one data chunk in flight to the receiver.
Thomas Graff8d96052011-07-07 00:28:35 +00001621 *
1622 * Allow the association to timeout while in SHUTDOWN
1623 * PENDING or SHUTDOWN RECEIVED in case the receiver
1624 * stays in zero window mode forever.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001625 */
1626 if (!q->asoc->peer.rwnd &&
1627 !list_empty(&tlist) &&
Thomas Graff8d96052011-07-07 00:28:35 +00001628 (sack_ctsn+2 == q->asoc->next_tsn) &&
1629 q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02001630 pr_debug("%s: sack received for zero window "
1631 "probe:%u\n", __func__, sack_ctsn);
1632
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 q->asoc->overall_error_count = 0;
1634 transport->error_count = 0;
1635 }
1636 }
1637
1638 /* RFC 2960 6.3.2 Retransmission Timer Rules
1639 *
1640 * R2) Whenever all outstanding data sent to an address have
1641 * been acknowledged, turn off the T3-rtx timer of that
1642 * address.
1643 */
1644 if (!transport->flight_size) {
Ying Xue25cc4ae2013-02-03 20:32:57 +00001645 if (del_timer(&transport->T3_rtx_timer))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646 sctp_transport_put(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647 } else if (restart_timer) {
1648 if (!mod_timer(&transport->T3_rtx_timer,
1649 jiffies + transport->rto))
1650 sctp_transport_hold(transport);
1651 }
Daniel Borkmann8c2f4142013-07-09 16:17:04 +02001652
1653 if (forward_progress) {
1654 if (transport->dst)
Julian Anastasovc86a7732017-02-06 23:14:13 +02001655 sctp_transport_dst_confirm(transport);
Daniel Borkmann8c2f4142013-07-09 16:17:04 +02001656 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657 }
1658
1659 list_splice(&tlist, transmitted_queue);
1660}
1661
1662/* Mark chunks as missing and consequently may get retransmitted. */
1663static void sctp_mark_missing(struct sctp_outq *q,
1664 struct list_head *transmitted_queue,
1665 struct sctp_transport *transport,
1666 __u32 highest_new_tsn_in_sack,
1667 int count_of_newacks)
1668{
1669 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 __u32 tsn;
1671 char do_fast_retransmit = 0;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001672 struct sctp_association *asoc = q->asoc;
1673 struct sctp_transport *primary = asoc->peer.primary_path;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001675 list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677 tsn = ntohl(chunk->subh.data_hdr->tsn);
1678
1679 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1680 * 'Unacknowledged TSN's', if the TSN number of an
1681 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1682 * value, increment the 'TSN.Missing.Report' count on that
1683 * chunk if it has NOT been fast retransmitted or marked for
1684 * fast retransmit already.
1685 */
Neil Hormanc226ef92008-07-25 12:44:09 -04001686 if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001687 !chunk->tsn_gap_acked &&
1688 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1689
1690 /* SFR-CACC may require us to skip marking
1691 * this chunk as missing.
1692 */
Vlad Yasevichf246a7b2011-04-18 19:13:56 +00001693 if (!transport || !sctp_cacc_skip(primary,
1694 chunk->transport,
1695 count_of_newacks, tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001696 chunk->tsn_missing_report++;
1697
Daniel Borkmannbb333812013-06-28 19:49:40 +02001698 pr_debug("%s: tsn:0x%x missing counter:%d\n",
1699 __func__, tsn, chunk->tsn_missing_report);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001700 }
1701 }
1702 /*
1703 * M4) If any DATA chunk is found to have a
1704 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001705 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 * retransmission and start the fast retransmit procedure.
1707 */
1708
Vlad Yasevich27852c22006-02-02 16:57:31 -08001709 if (chunk->tsn_missing_report >= 3) {
Neil Hormanc226ef92008-07-25 12:44:09 -04001710 chunk->fast_retransmit = SCTP_NEED_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 do_fast_retransmit = 1;
1712 }
1713 }
1714
1715 if (transport) {
1716 if (do_fast_retransmit)
1717 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1718
Daniel Borkmannbb333812013-06-28 19:49:40 +02001719 pr_debug("%s: transport:%p, cwnd:%d, ssthresh:%d, "
1720 "flight_size:%d, pba:%d\n", __func__, transport,
1721 transport->cwnd, transport->ssthresh,
1722 transport->flight_size, transport->partial_bytes_acked);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723 }
1724}
1725
1726/* Is the given TSN acked by this packet? */
1727static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1728{
1729 int i;
1730 sctp_sack_variable_t *frags;
Marcelo Ricardo Leitnera3007442016-09-20 18:19:13 -03001731 __u16 tsn_offset, blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1733
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001734 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 goto pass;
1736
1737 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1738 *
1739 * Gap Ack Blocks:
1740 * These fields contain the Gap Ack Blocks. They are repeated
1741 * for each Gap Ack Block up to the number of Gap Ack Blocks
1742 * defined in the Number of Gap Ack Blocks field. All DATA
1743 * chunks with TSNs greater than or equal to (Cumulative TSN
1744 * Ack + Gap Ack Block Start) and less than or equal to
1745 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1746 * Block are assumed to have been received correctly.
1747 */
1748
1749 frags = sack->variable;
Marcelo Ricardo Leitnera3007442016-09-20 18:19:13 -03001750 blocks = ntohs(sack->num_gap_ack_blocks);
1751 tsn_offset = tsn - ctsn;
1752 for (i = 0; i < blocks; ++i) {
1753 if (tsn_offset >= ntohs(frags[i].gab.start) &&
1754 tsn_offset <= ntohs(frags[i].gab.end))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001755 goto pass;
1756 }
1757
1758 return 0;
1759pass:
1760 return 1;
1761}
1762
1763static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001764 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765{
1766 int i;
1767
1768 for (i = 0; i < nskips; i++) {
1769 if (skiplist[i].stream == stream)
1770 return i;
1771 }
1772 return i;
1773}
1774
1775/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1776static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1777{
1778 struct sctp_association *asoc = q->asoc;
1779 struct sctp_chunk *ftsn_chunk = NULL;
1780 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1781 int nskips = 0;
1782 int skip_pos = 0;
1783 __u32 tsn;
1784 struct sctp_chunk *chunk;
1785 struct list_head *lchunk, *temp;
1786
Wei Yongjun76595022009-03-12 09:49:19 +00001787 if (!asoc->peer.prsctp_capable)
1788 return;
1789
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1791 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001792 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1794 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1795 */
1796 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1797 asoc->adv_peer_ack_point = ctsn;
1798
1799 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1800 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1801 * the chunk next in the out-queue space is marked as "abandoned" as
1802 * shown in the following example:
1803 *
1804 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1805 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001806 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1808 * normal SACK processing local advancement
1809 * ... ...
1810 * Adv.Ack.Pt-> 102 acked 102 acked
1811 * 103 abandoned 103 abandoned
1812 * 104 abandoned Adv.Ack.P-> 104 abandoned
1813 * 105 105
1814 * 106 acked 106 acked
1815 * ... ...
1816 *
1817 * In this example, the data sender successfully advanced the
1818 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1819 */
1820 list_for_each_safe(lchunk, temp, &q->abandoned) {
1821 chunk = list_entry(lchunk, struct sctp_chunk,
1822 transmitted_list);
1823 tsn = ntohl(chunk->subh.data_hdr->tsn);
1824
1825 /* Remove any chunks in the abandoned queue that are acked by
1826 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001827 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828 if (TSN_lte(tsn, ctsn)) {
1829 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001830 sctp_chunk_free(chunk);
1831 } else {
1832 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1833 asoc->adv_peer_ack_point = tsn;
1834 if (chunk->chunk_hdr->flags &
1835 SCTP_DATA_UNORDERED)
1836 continue;
1837 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1838 nskips,
1839 chunk->subh.data_hdr->stream);
1840 ftsn_skip_arr[skip_pos].stream =
1841 chunk->subh.data_hdr->stream;
1842 ftsn_skip_arr[skip_pos].ssn =
1843 chunk->subh.data_hdr->ssn;
1844 if (skip_pos == nskips)
1845 nskips++;
1846 if (nskips == 10)
1847 break;
1848 } else
1849 break;
1850 }
1851 }
1852
1853 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1854 * is greater than the Cumulative TSN ACK carried in the received
1855 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1856 * chunk containing the latest value of the
1857 * "Advanced.Peer.Ack.Point".
1858 *
1859 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1860 * list each stream and sequence number in the forwarded TSN. This
1861 * information will enable the receiver to easily find any
1862 * stranded TSN's waiting on stream reorder queues. Each stream
1863 * SHOULD only be reported once; this means that if multiple
1864 * abandoned messages occur in the same stream then only the
1865 * highest abandoned stream sequence number is reported. If the
1866 * total size of the FORWARD TSN does NOT fit in a single MTU then
1867 * the sender of the FORWARD TSN SHOULD lower the
1868 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1869 * single MTU.
1870 */
1871 if (asoc->adv_peer_ack_point > ctsn)
1872 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001873 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001874
1875 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001876 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00001877 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878 }
1879}