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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
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 | * | |
60c778b2 | 7 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
8 | * |
9 | * These functions implement the sctp_outq class. The outqueue handles | |
10 | * bundling and queueing of outgoing SCTP chunks. | |
11 | * | |
60c778b2 | 12 | * This SCTP implementation is free software; |
1da177e4 LT |
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 | * | |
60c778b2 | 18 | * This SCTP implementation is distributed in the hope that it |
1da177e4 LT |
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 | |
4b2f13a2 JK |
25 | * along with GNU CC; see the file COPYING. If not, see |
26 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
27 | * |
28 | * Please send any bug reports or fixes you make to the | |
29 | * email address(es): | |
91705c61 | 30 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 31 | * |
1da177e4 LT |
32 | * 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> | |
1da177e4 LT |
40 | */ |
41 | ||
145ce502 JP |
42 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
43 | ||
1da177e4 LT |
44 | #include <linux/types.h> |
45 | #include <linux/list.h> /* For struct list_head */ | |
46 | #include <linux/socket.h> | |
47 | #include <linux/ip.h> | |
5a0e3ad6 | 48 | #include <linux/slab.h> |
1da177e4 LT |
49 | #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. */ | |
55 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); | |
56 | static void sctp_check_transmitted(struct sctp_outq *q, | |
57 | struct list_head *transmitted_queue, | |
58 | struct sctp_transport *transport, | |
edfee033 | 59 | union sctp_addr *saddr, |
1da177e4 | 60 | struct sctp_sackhdr *sack, |
bfa0d984 | 61 | __u32 *highest_new_tsn); |
1da177e4 LT |
62 | |
63 | static 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 | ||
69 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); | |
70 | ||
abd0b198 AB |
71 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout); |
72 | ||
1da177e4 LT |
73 | /* Add data to the front of the queue. */ |
74 | static inline void sctp_outq_head_data(struct sctp_outq *q, | |
75 | struct sctp_chunk *ch) | |
76 | { | |
79af02c2 | 77 | list_add(&ch->list, &q->out_chunk_list); |
1da177e4 | 78 | q->out_qlen += ch->skb->len; |
1da177e4 LT |
79 | } |
80 | ||
81 | /* Take data from the front of the queue. */ | |
82 | static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) | |
83 | { | |
79af02c2 DM |
84 | 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); | |
1da177e4 | 91 | q->out_qlen -= ch->skb->len; |
79af02c2 | 92 | } |
1da177e4 LT |
93 | return ch; |
94 | } | |
95 | /* Add data chunk to the end of the queue. */ | |
96 | static inline void sctp_outq_tail_data(struct sctp_outq *q, | |
97 | struct sctp_chunk *ch) | |
98 | { | |
79af02c2 | 99 | list_add_tail(&ch->list, &q->out_chunk_list); |
1da177e4 | 100 | q->out_qlen += ch->skb->len; |
1da177e4 LT |
101 | } |
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 | */ | |
109 | static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, | |
110 | struct sctp_transport *transport, | |
111 | int count_of_newacks) | |
112 | { | |
cb3f837b | 113 | if (count_of_newacks >= 2 && transport != primary) |
1da177e4 LT |
114 | 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 | */ | |
125 | static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, | |
126 | int count_of_newacks) | |
127 | { | |
f246a7b7 VY |
128 | if (count_of_newacks < 2 && |
129 | (transport && !transport->cacc.cacc_saw_newack)) | |
1da177e4 LT |
130 | 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 | */ | |
141 | static 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 | */ | |
162 | static 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, | |
25985edc | 175 | * then the sender MUST further execute steps 3.1 and |
1da177e4 LT |
176 | * 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 | |
25985edc | 181 | * the sender SHOULD increment missing report count for |
1da177e4 LT |
182 | * t (according to [RFC2960] and [SCTP_STEWART_2002]). |
183 | */ | |
184 | static 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 && | |
f64f9e71 JP |
190 | (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) || |
191 | sctp_cacc_skip_3_2(primary, tsn))) | |
1da177e4 LT |
192 | 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 | */ | |
200 | void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) | |
201 | { | |
c5c7774d NH |
202 | memset(q, 0, sizeof(struct sctp_outq)); |
203 | ||
1da177e4 | 204 | q->asoc = asoc; |
79af02c2 DM |
205 | INIT_LIST_HEAD(&q->out_chunk_list); |
206 | INIT_LIST_HEAD(&q->control_chunk_list); | |
1da177e4 LT |
207 | INIT_LIST_HEAD(&q->retransmit); |
208 | INIT_LIST_HEAD(&q->sacked); | |
209 | INIT_LIST_HEAD(&q->abandoned); | |
1da177e4 LT |
210 | } |
211 | ||
212 | /* Free the outqueue structure and any related pending chunks. | |
213 | */ | |
2f94aabd | 214 | static void __sctp_outq_teardown(struct sctp_outq *q) |
1da177e4 LT |
215 | { |
216 | struct sctp_transport *transport; | |
9dbc15f0 | 217 | struct list_head *lchunk, *temp; |
79af02c2 | 218 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
219 | |
220 | /* Throw away unacknowledged chunks. */ | |
9dbc15f0 RD |
221 | list_for_each_entry(transport, &q->asoc->peer.transport_addr_list, |
222 | transports) { | |
1da177e4 LT |
223 | 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 | ||
1da177e4 | 267 | /* Throw away any leftover control chunks. */ |
79af02c2 DM |
268 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
269 | list_del_init(&chunk->list); | |
1da177e4 | 270 | sctp_chunk_free(chunk); |
79af02c2 | 271 | } |
1da177e4 LT |
272 | } |
273 | ||
2f94aabd NH |
274 | void sctp_outq_teardown(struct sctp_outq *q) |
275 | { | |
276 | __sctp_outq_teardown(q); | |
277 | sctp_outq_init(q->asoc, q); | |
278 | } | |
279 | ||
1da177e4 LT |
280 | /* Free the outqueue structure and any related pending chunks. */ |
281 | void sctp_outq_free(struct sctp_outq *q) | |
282 | { | |
283 | /* Throw away leftover chunks. */ | |
2f94aabd | 284 | __sctp_outq_teardown(q); |
1da177e4 LT |
285 | } |
286 | ||
287 | /* Put a new chunk in an sctp_outq. */ | |
288 | int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) | |
289 | { | |
b01a2407 | 290 | struct net *net = sock_net(q->asoc->base.sk); |
1da177e4 LT |
291 | int error = 0; |
292 | ||
bb33381d DB |
293 | pr_debug("%s: outq:%p, chunk:%p[%s]\n", __func__, q, chunk, |
294 | chunk && chunk->chunk_hdr ? | |
295 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
296 | "illegal chunk"); | |
1da177e4 LT |
297 | |
298 | /* If it is data, queue it up, otherwise, send it | |
299 | * immediately. | |
300 | */ | |
ec7b9519 | 301 | if (sctp_chunk_is_data(chunk)) { |
1da177e4 LT |
302 | /* Is it OK to queue data chunks? */ |
303 | /* From 9. Termination of Association | |
304 | * | |
305 | * When either endpoint performs a shutdown, the | |
306 | * association on each peer will stop accepting new | |
307 | * data from its user and only deliver data in queue | |
308 | * at the time of sending or receiving the SHUTDOWN | |
309 | * chunk. | |
310 | */ | |
311 | switch (q->asoc->state) { | |
1da177e4 LT |
312 | case SCTP_STATE_CLOSED: |
313 | case SCTP_STATE_SHUTDOWN_PENDING: | |
314 | case SCTP_STATE_SHUTDOWN_SENT: | |
315 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
316 | case SCTP_STATE_SHUTDOWN_ACK_SENT: | |
317 | /* Cannot send after transport endpoint shutdown */ | |
318 | error = -ESHUTDOWN; | |
319 | break; | |
320 | ||
321 | default: | |
bb33381d DB |
322 | pr_debug("%s: outqueueing: outq:%p, chunk:%p[%s])\n", |
323 | __func__, q, chunk, chunk && chunk->chunk_hdr ? | |
324 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
325 | "illegal chunk"); | |
1da177e4 LT |
326 | |
327 | sctp_outq_tail_data(q, chunk); | |
328 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
b01a2407 | 329 | SCTP_INC_STATS(net, SCTP_MIB_OUTUNORDERCHUNKS); |
1da177e4 | 330 | else |
b01a2407 | 331 | SCTP_INC_STATS(net, SCTP_MIB_OUTORDERCHUNKS); |
1da177e4 | 332 | break; |
3ff50b79 | 333 | } |
1da177e4 | 334 | } else { |
79af02c2 | 335 | list_add_tail(&chunk->list, &q->control_chunk_list); |
b01a2407 | 336 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
337 | } |
338 | ||
339 | if (error < 0) | |
340 | return error; | |
341 | ||
342 | if (!q->cork) | |
343 | error = sctp_outq_flush(q, 0); | |
344 | ||
345 | return error; | |
346 | } | |
347 | ||
348 | /* Insert a chunk into the sorted list based on the TSNs. The retransmit list | |
349 | * and the abandoned list are in ascending order. | |
350 | */ | |
351 | static void sctp_insert_list(struct list_head *head, struct list_head *new) | |
352 | { | |
353 | struct list_head *pos; | |
354 | struct sctp_chunk *nchunk, *lchunk; | |
355 | __u32 ntsn, ltsn; | |
356 | int done = 0; | |
357 | ||
358 | nchunk = list_entry(new, struct sctp_chunk, transmitted_list); | |
359 | ntsn = ntohl(nchunk->subh.data_hdr->tsn); | |
360 | ||
361 | list_for_each(pos, head) { | |
362 | lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); | |
363 | ltsn = ntohl(lchunk->subh.data_hdr->tsn); | |
364 | if (TSN_lt(ntsn, ltsn)) { | |
365 | list_add(new, pos->prev); | |
366 | done = 1; | |
367 | break; | |
368 | } | |
369 | } | |
370 | if (!done) | |
d808ad9a | 371 | list_add_tail(new, head); |
1da177e4 LT |
372 | } |
373 | ||
374 | /* Mark all the eligible packets on a transport for retransmission. */ | |
375 | void sctp_retransmit_mark(struct sctp_outq *q, | |
376 | struct sctp_transport *transport, | |
b6157d8e | 377 | __u8 reason) |
1da177e4 LT |
378 | { |
379 | struct list_head *lchunk, *ltemp; | |
380 | struct sctp_chunk *chunk; | |
381 | ||
382 | /* Walk through the specified transmitted queue. */ | |
383 | list_for_each_safe(lchunk, ltemp, &transport->transmitted) { | |
384 | chunk = list_entry(lchunk, struct sctp_chunk, | |
385 | transmitted_list); | |
386 | ||
387 | /* If the chunk is abandoned, move it to abandoned list. */ | |
388 | if (sctp_chunk_abandoned(chunk)) { | |
389 | list_del_init(lchunk); | |
390 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
391 | |
392 | /* If this chunk has not been previousely acked, | |
393 | * stop considering it 'outstanding'. Our peer | |
394 | * will most likely never see it since it will | |
395 | * not be retransmitted | |
396 | */ | |
397 | if (!chunk->tsn_gap_acked) { | |
31b02e15 VY |
398 | if (chunk->transport) |
399 | chunk->transport->flight_size -= | |
400 | sctp_data_size(chunk); | |
8c4a2d41 | 401 | q->outstanding_bytes -= sctp_data_size(chunk); |
a76c0adf | 402 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
8c4a2d41 | 403 | } |
1da177e4 LT |
404 | continue; |
405 | } | |
406 | ||
b6157d8e VY |
407 | /* If we are doing retransmission due to a timeout or pmtu |
408 | * discovery, only the chunks that are not yet acked should | |
409 | * be added to the retransmit queue. | |
1da177e4 | 410 | */ |
b6157d8e | 411 | if ((reason == SCTP_RTXR_FAST_RTX && |
c226ef9b | 412 | (chunk->fast_retransmit == SCTP_NEED_FRTX)) || |
b6157d8e | 413 | (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) { |
1da177e4 LT |
414 | /* RFC 2960 6.2.1 Processing a Received SACK |
415 | * | |
416 | * C) Any time a DATA chunk is marked for | |
417 | * retransmission (via either T3-rtx timer expiration | |
418 | * (Section 6.3.3) or via fast retransmit | |
419 | * (Section 7.2.4)), add the data size of those | |
420 | * chunks to the rwnd. | |
421 | */ | |
a76c0adf | 422 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
1da177e4 | 423 | q->outstanding_bytes -= sctp_data_size(chunk); |
31b02e15 VY |
424 | if (chunk->transport) |
425 | transport->flight_size -= sctp_data_size(chunk); | |
1da177e4 LT |
426 | |
427 | /* sctpimpguide-05 Section 2.8.2 | |
428 | * M5) If a T3-rtx timer expires, the | |
429 | * 'TSN.Missing.Report' of all affected TSNs is set | |
430 | * to 0. | |
431 | */ | |
432 | chunk->tsn_missing_report = 0; | |
433 | ||
434 | /* If a chunk that is being used for RTT measurement | |
435 | * has to be retransmitted, we cannot use this chunk | |
436 | * anymore for RTT measurements. Reset rto_pending so | |
437 | * that a new RTT measurement is started when a new | |
438 | * data chunk is sent. | |
439 | */ | |
440 | if (chunk->rtt_in_progress) { | |
441 | chunk->rtt_in_progress = 0; | |
442 | transport->rto_pending = 0; | |
443 | } | |
444 | ||
6eabca54 XZ |
445 | chunk->resent = 1; |
446 | ||
1da177e4 LT |
447 | /* Move the chunk to the retransmit queue. The chunks |
448 | * on the retransmit queue are always kept in order. | |
449 | */ | |
450 | list_del_init(lchunk); | |
451 | sctp_insert_list(&q->retransmit, lchunk); | |
452 | } | |
453 | } | |
454 | ||
bb33381d DB |
455 | pr_debug("%s: transport:%p, reason:%d, cwnd:%d, ssthresh:%d, " |
456 | "flight_size:%d, pba:%d\n", __func__, transport, reason, | |
457 | transport->cwnd, transport->ssthresh, transport->flight_size, | |
458 | transport->partial_bytes_acked); | |
1da177e4 LT |
459 | } |
460 | ||
461 | /* Mark all the eligible packets on a transport for retransmission and force | |
462 | * one packet out. | |
463 | */ | |
464 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, | |
465 | sctp_retransmit_reason_t reason) | |
466 | { | |
b01a2407 | 467 | struct net *net = sock_net(q->asoc->base.sk); |
1da177e4 | 468 | int error = 0; |
1da177e4 | 469 | |
cb3f837b | 470 | switch (reason) { |
1da177e4 | 471 | case SCTP_RTXR_T3_RTX: |
b01a2407 | 472 | SCTP_INC_STATS(net, SCTP_MIB_T3_RETRANSMITS); |
1da177e4 LT |
473 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); |
474 | /* Update the retran path if the T3-rtx timer has expired for | |
475 | * the current retran path. | |
476 | */ | |
477 | if (transport == transport->asoc->peer.retran_path) | |
478 | sctp_assoc_update_retran_path(transport->asoc); | |
58fbbed4 NH |
479 | transport->asoc->rtx_data_chunks += |
480 | transport->asoc->unack_data; | |
1da177e4 LT |
481 | break; |
482 | case SCTP_RTXR_FAST_RTX: | |
b01a2407 | 483 | SCTP_INC_STATS(net, SCTP_MIB_FAST_RETRANSMITS); |
1da177e4 | 484 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); |
62aeaff5 | 485 | q->fast_rtx = 1; |
1da177e4 LT |
486 | break; |
487 | case SCTP_RTXR_PMTUD: | |
b01a2407 | 488 | SCTP_INC_STATS(net, SCTP_MIB_PMTUD_RETRANSMITS); |
1da177e4 | 489 | break; |
b6157d8e | 490 | case SCTP_RTXR_T1_RTX: |
b01a2407 | 491 | SCTP_INC_STATS(net, SCTP_MIB_T1_RETRANSMITS); |
58fbbed4 | 492 | transport->asoc->init_retries++; |
b6157d8e | 493 | break; |
ac0b0462 SS |
494 | default: |
495 | BUG(); | |
1da177e4 LT |
496 | } |
497 | ||
b6157d8e | 498 | sctp_retransmit_mark(q, transport, reason); |
1da177e4 LT |
499 | |
500 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, | |
501 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by | |
502 | * following the procedures outlined in C1 - C5. | |
503 | */ | |
8b750ce5 VY |
504 | if (reason == SCTP_RTXR_T3_RTX) |
505 | sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); | |
1da177e4 | 506 | |
8b750ce5 VY |
507 | /* Flush the queues only on timeout, since fast_rtx is only |
508 | * triggered during sack processing and the queue | |
509 | * will be flushed at the end. | |
510 | */ | |
511 | if (reason != SCTP_RTXR_FAST_RTX) | |
512 | error = sctp_outq_flush(q, /* rtx_timeout */ 1); | |
1da177e4 LT |
513 | |
514 | if (error) | |
515 | q->asoc->base.sk->sk_err = -error; | |
516 | } | |
517 | ||
518 | /* | |
519 | * Transmit DATA chunks on the retransmit queue. Upon return from | |
520 | * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which | |
521 | * need to be transmitted by the caller. | |
522 | * We assume that pkt->transport has already been set. | |
523 | * | |
524 | * The return value is a normal kernel error return value. | |
525 | */ | |
526 | static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, | |
527 | int rtx_timeout, int *start_timer) | |
528 | { | |
529 | struct list_head *lqueue; | |
1da177e4 LT |
530 | struct sctp_transport *transport = pkt->transport; |
531 | sctp_xmit_t status; | |
532 | struct sctp_chunk *chunk, *chunk1; | |
62aeaff5 | 533 | int fast_rtx; |
1da177e4 | 534 | int error = 0; |
62aeaff5 | 535 | int timer = 0; |
8b750ce5 | 536 | int done = 0; |
1da177e4 | 537 | |
1da177e4 | 538 | lqueue = &q->retransmit; |
62aeaff5 | 539 | fast_rtx = q->fast_rtx; |
1da177e4 | 540 | |
8b750ce5 VY |
541 | /* This loop handles time-out retransmissions, fast retransmissions, |
542 | * and retransmissions due to opening of whindow. | |
543 | * | |
544 | * RFC 2960 6.3.3 Handle T3-rtx Expiration | |
1da177e4 LT |
545 | * |
546 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
547 | * outstanding DATA chunks for the address for which the | |
548 | * T3-rtx has expired will fit into a single packet, subject | |
549 | * to the MTU constraint for the path corresponding to the | |
550 | * destination transport address to which the retransmission | |
551 | * is being sent (this may be different from the address for | |
552 | * which the timer expires [see Section 6.4]). Call this value | |
553 | * K. Bundle and retransmit those K DATA chunks in a single | |
554 | * packet to the destination endpoint. | |
555 | * | |
556 | * [Just to be painfully clear, if we are retransmitting | |
557 | * because a timeout just happened, we should send only ONE | |
558 | * packet of retransmitted data.] | |
8b750ce5 VY |
559 | * |
560 | * For fast retransmissions we also send only ONE packet. However, | |
561 | * if we are just flushing the queue due to open window, we'll | |
562 | * try to send as much as possible. | |
1da177e4 | 563 | */ |
8b750ce5 | 564 | list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { |
4c6a6f42 WY |
565 | /* If the chunk is abandoned, move it to abandoned list. */ |
566 | if (sctp_chunk_abandoned(chunk)) { | |
567 | list_del_init(&chunk->transmitted_list); | |
568 | sctp_insert_list(&q->abandoned, | |
569 | &chunk->transmitted_list); | |
570 | continue; | |
571 | } | |
1da177e4 LT |
572 | |
573 | /* Make sure that Gap Acked TSNs are not retransmitted. A | |
574 | * simple approach is just to move such TSNs out of the | |
575 | * way and into a 'transmitted' queue and skip to the | |
576 | * next chunk. | |
577 | */ | |
578 | if (chunk->tsn_gap_acked) { | |
54a27924 WY |
579 | list_move_tail(&chunk->transmitted_list, |
580 | &transport->transmitted); | |
1da177e4 LT |
581 | continue; |
582 | } | |
583 | ||
8b750ce5 VY |
584 | /* If we are doing fast retransmit, ignore non-fast_rtransmit |
585 | * chunks | |
586 | */ | |
587 | if (fast_rtx && !chunk->fast_retransmit) | |
588 | continue; | |
589 | ||
bc4f841a | 590 | redo: |
1da177e4 LT |
591 | /* Attempt to append this chunk to the packet. */ |
592 | status = sctp_packet_append_chunk(pkt, chunk); | |
593 | ||
594 | switch (status) { | |
595 | case SCTP_XMIT_PMTU_FULL: | |
bc4f841a WY |
596 | if (!pkt->has_data && !pkt->has_cookie_echo) { |
597 | /* If this packet did not contain DATA then | |
598 | * retransmission did not happen, so do it | |
599 | * again. We'll ignore the error here since | |
600 | * control chunks are already freed so there | |
601 | * is nothing we can do. | |
602 | */ | |
603 | sctp_packet_transmit(pkt); | |
604 | goto redo; | |
605 | } | |
606 | ||
1da177e4 | 607 | /* Send this packet. */ |
62aeaff5 | 608 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
609 | |
610 | /* If we are retransmitting, we should only | |
611 | * send a single packet. | |
f246a7b7 | 612 | * Otherwise, try appending this chunk again. |
1da177e4 | 613 | */ |
8b750ce5 VY |
614 | if (rtx_timeout || fast_rtx) |
615 | done = 1; | |
f246a7b7 VY |
616 | else |
617 | goto redo; | |
1da177e4 | 618 | |
8b750ce5 | 619 | /* Bundle next chunk in the next round. */ |
1da177e4 LT |
620 | break; |
621 | ||
622 | case SCTP_XMIT_RWND_FULL: | |
d808ad9a | 623 | /* Send this packet. */ |
62aeaff5 | 624 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
625 | |
626 | /* Stop sending DATA as there is no more room | |
627 | * at the receiver. | |
628 | */ | |
8b750ce5 | 629 | done = 1; |
1da177e4 LT |
630 | break; |
631 | ||
526cbef7 | 632 | case SCTP_XMIT_DELAY: |
d808ad9a | 633 | /* Send this packet. */ |
62aeaff5 | 634 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
635 | |
636 | /* Stop sending DATA because of nagle delay. */ | |
8b750ce5 | 637 | done = 1; |
1da177e4 LT |
638 | break; |
639 | ||
640 | default: | |
641 | /* The append was successful, so add this chunk to | |
642 | * the transmitted list. | |
643 | */ | |
54a27924 WY |
644 | list_move_tail(&chunk->transmitted_list, |
645 | &transport->transmitted); | |
1da177e4 | 646 | |
d808ad9a | 647 | /* Mark the chunk as ineligible for fast retransmit |
1da177e4 LT |
648 | * after it is retransmitted. |
649 | */ | |
c226ef9b NH |
650 | if (chunk->fast_retransmit == SCTP_NEED_FRTX) |
651 | chunk->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 | 652 | |
196d6759 | 653 | q->asoc->stats.rtxchunks++; |
1da177e4 | 654 | break; |
3ff50b79 | 655 | } |
1da177e4 | 656 | |
62aeaff5 VY |
657 | /* Set the timer if there were no errors */ |
658 | if (!error && !timer) | |
659 | timer = 1; | |
660 | ||
8b750ce5 VY |
661 | if (done) |
662 | break; | |
663 | } | |
664 | ||
665 | /* If we are here due to a retransmit timeout or a fast | |
666 | * retransmit and if there are any chunks left in the retransmit | |
667 | * queue that could not fit in the PMTU sized packet, they need | |
668 | * to be marked as ineligible for a subsequent fast retransmit. | |
669 | */ | |
670 | if (rtx_timeout || fast_rtx) { | |
671 | list_for_each_entry(chunk1, lqueue, transmitted_list) { | |
c226ef9b NH |
672 | if (chunk1->fast_retransmit == SCTP_NEED_FRTX) |
673 | chunk1->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 LT |
674 | } |
675 | } | |
676 | ||
62aeaff5 VY |
677 | *start_timer = timer; |
678 | ||
679 | /* Clear fast retransmit hint */ | |
680 | if (fast_rtx) | |
681 | q->fast_rtx = 0; | |
682 | ||
1da177e4 LT |
683 | return error; |
684 | } | |
685 | ||
686 | /* Cork the outqueue so queued chunks are really queued. */ | |
687 | int sctp_outq_uncork(struct sctp_outq *q) | |
688 | { | |
7d54dc68 | 689 | if (q->cork) |
1da177e4 | 690 | q->cork = 0; |
dacda32e DB |
691 | |
692 | return sctp_outq_flush(q, 0); | |
1da177e4 LT |
693 | } |
694 | ||
2e3216cd | 695 | |
1da177e4 LT |
696 | /* |
697 | * Try to flush an outqueue. | |
698 | * | |
699 | * Description: Send everything in q which we legally can, subject to | |
700 | * congestion limitations. | |
701 | * * Note: This function can be called from multiple contexts so appropriate | |
702 | * locking concerns must be made. Today we use the sock lock to protect | |
703 | * this function. | |
704 | */ | |
abd0b198 | 705 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) |
1da177e4 LT |
706 | { |
707 | struct sctp_packet *packet; | |
708 | struct sctp_packet singleton; | |
709 | struct sctp_association *asoc = q->asoc; | |
710 | __u16 sport = asoc->base.bind_addr.port; | |
711 | __u16 dport = asoc->peer.port; | |
712 | __u32 vtag = asoc->peer.i.init_tag; | |
1da177e4 LT |
713 | struct sctp_transport *transport = NULL; |
714 | struct sctp_transport *new_transport; | |
79af02c2 | 715 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
716 | sctp_xmit_t status; |
717 | int error = 0; | |
718 | int start_timer = 0; | |
2e3216cd | 719 | int one_packet = 0; |
1da177e4 LT |
720 | |
721 | /* These transports have chunks to send. */ | |
722 | struct list_head transport_list; | |
723 | struct list_head *ltransport; | |
724 | ||
725 | INIT_LIST_HEAD(&transport_list); | |
726 | packet = NULL; | |
727 | ||
728 | /* | |
729 | * 6.10 Bundling | |
730 | * ... | |
731 | * When bundling control chunks with DATA chunks, an | |
732 | * endpoint MUST place control chunks first in the outbound | |
733 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
734 | * within a SCTP packet in increasing order of TSN. | |
735 | * ... | |
736 | */ | |
737 | ||
79af02c2 | 738 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
8a07eb0a MH |
739 | /* RFC 5061, 5.3 |
740 | * F1) This means that until such time as the ASCONF | |
741 | * containing the add is acknowledged, the sender MUST | |
742 | * NOT use the new IP address as a source for ANY SCTP | |
743 | * packet except on carrying an ASCONF Chunk. | |
744 | */ | |
745 | if (asoc->src_out_of_asoc_ok && | |
746 | chunk->chunk_hdr->type != SCTP_CID_ASCONF) | |
747 | continue; | |
748 | ||
79af02c2 DM |
749 | list_del_init(&chunk->list); |
750 | ||
1da177e4 LT |
751 | /* Pick the right transport to use. */ |
752 | new_transport = chunk->transport; | |
753 | ||
754 | if (!new_transport) { | |
a08de64d VY |
755 | /* |
756 | * If we have a prior transport pointer, see if | |
757 | * the destination address of the chunk | |
758 | * matches the destination address of the | |
759 | * current transport. If not a match, then | |
760 | * try to look up the transport with a given | |
761 | * destination address. We do this because | |
762 | * after processing ASCONFs, we may have new | |
763 | * transports created. | |
764 | */ | |
765 | if (transport && | |
766 | sctp_cmp_addr_exact(&chunk->dest, | |
767 | &transport->ipaddr)) | |
768 | new_transport = transport; | |
769 | else | |
770 | new_transport = sctp_assoc_lookup_paddr(asoc, | |
771 | &chunk->dest); | |
772 | ||
773 | /* if we still don't have a new transport, then | |
774 | * use the current active path. | |
775 | */ | |
776 | if (!new_transport) | |
777 | new_transport = asoc->peer.active_path; | |
ad8fec17 | 778 | } else if ((new_transport->state == SCTP_INACTIVE) || |
5aa93bcf NH |
779 | (new_transport->state == SCTP_UNCONFIRMED) || |
780 | (new_transport->state == SCTP_PF)) { | |
3f7a87d2 FF |
781 | /* If the chunk is Heartbeat or Heartbeat Ack, |
782 | * send it to chunk->transport, even if it's | |
1da177e4 LT |
783 | * inactive. |
784 | * | |
785 | * 3.3.6 Heartbeat Acknowledgement: | |
d808ad9a | 786 | * ... |
1da177e4 LT |
787 | * A HEARTBEAT ACK is always sent to the source IP |
788 | * address of the IP datagram containing the | |
789 | * HEARTBEAT chunk to which this ack is responding. | |
d808ad9a | 790 | * ... |
a08de64d VY |
791 | * |
792 | * ASCONF_ACKs also must be sent to the source. | |
1da177e4 LT |
793 | */ |
794 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && | |
a08de64d VY |
795 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK && |
796 | chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK) | |
1da177e4 LT |
797 | new_transport = asoc->peer.active_path; |
798 | } | |
799 | ||
800 | /* Are we switching transports? | |
801 | * Take care of transport locks. | |
802 | */ | |
803 | if (new_transport != transport) { | |
804 | transport = new_transport; | |
805 | if (list_empty(&transport->send_ready)) { | |
806 | list_add_tail(&transport->send_ready, | |
807 | &transport_list); | |
808 | } | |
809 | packet = &transport->packet; | |
810 | sctp_packet_config(packet, vtag, | |
811 | asoc->peer.ecn_capable); | |
812 | } | |
813 | ||
814 | switch (chunk->chunk_hdr->type) { | |
815 | /* | |
816 | * 6.10 Bundling | |
817 | * ... | |
818 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
819 | * COMPLETE with any other chunks. [Send them immediately.] | |
820 | */ | |
821 | case SCTP_CID_INIT: | |
822 | case SCTP_CID_INIT_ACK: | |
823 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
824 | sctp_packet_init(&singleton, transport, sport, dport); | |
825 | sctp_packet_config(&singleton, vtag, 0); | |
826 | sctp_packet_append_chunk(&singleton, chunk); | |
827 | error = sctp_packet_transmit(&singleton); | |
828 | if (error < 0) | |
829 | return error; | |
830 | break; | |
831 | ||
832 | case SCTP_CID_ABORT: | |
f4ad85ca GJ |
833 | if (sctp_test_T_bit(chunk)) { |
834 | packet->vtag = asoc->c.my_vtag; | |
835 | } | |
2e3216cd VY |
836 | /* The following chunks are "response" chunks, i.e. |
837 | * they are generated in response to something we | |
838 | * received. If we are sending these, then we can | |
839 | * send only 1 packet containing these chunks. | |
840 | */ | |
1da177e4 | 841 | case SCTP_CID_HEARTBEAT_ACK: |
1da177e4 | 842 | case SCTP_CID_SHUTDOWN_ACK: |
1da177e4 | 843 | case SCTP_CID_COOKIE_ACK: |
2e3216cd VY |
844 | case SCTP_CID_COOKIE_ECHO: |
845 | case SCTP_CID_ERROR: | |
1da177e4 | 846 | case SCTP_CID_ECN_CWR: |
1da177e4 | 847 | case SCTP_CID_ASCONF_ACK: |
2e3216cd | 848 | one_packet = 1; |
25985edc | 849 | /* Fall through */ |
2e3216cd VY |
850 | |
851 | case SCTP_CID_SACK: | |
852 | case SCTP_CID_HEARTBEAT: | |
853 | case SCTP_CID_SHUTDOWN: | |
854 | case SCTP_CID_ECN_ECNE: | |
855 | case SCTP_CID_ASCONF: | |
1da177e4 | 856 | case SCTP_CID_FWD_TSN: |
2e3216cd VY |
857 | status = sctp_packet_transmit_chunk(packet, chunk, |
858 | one_packet); | |
859 | if (status != SCTP_XMIT_OK) { | |
860 | /* put the chunk back */ | |
861 | list_add(&chunk->list, &q->control_chunk_list); | |
196d6759 MB |
862 | } else { |
863 | asoc->stats.octrlchunks++; | |
bd69b981 WY |
864 | /* PR-SCTP C5) If a FORWARD TSN is sent, the |
865 | * sender MUST assure that at least one T3-rtx | |
866 | * timer is running. | |
867 | */ | |
196d6759 MB |
868 | if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) |
869 | sctp_transport_reset_timers(transport); | |
2e3216cd | 870 | } |
1da177e4 LT |
871 | break; |
872 | ||
873 | default: | |
874 | /* We built a chunk with an illegal type! */ | |
875 | BUG(); | |
3ff50b79 | 876 | } |
1da177e4 LT |
877 | } |
878 | ||
8a07eb0a MH |
879 | if (q->asoc->src_out_of_asoc_ok) |
880 | goto sctp_flush_out; | |
881 | ||
1da177e4 LT |
882 | /* Is it OK to send data chunks? */ |
883 | switch (asoc->state) { | |
884 | case SCTP_STATE_COOKIE_ECHOED: | |
885 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
886 | * chunk. | |
887 | */ | |
888 | if (!packet || !packet->has_cookie_echo) | |
889 | break; | |
890 | ||
891 | /* fallthru */ | |
892 | case SCTP_STATE_ESTABLISHED: | |
893 | case SCTP_STATE_SHUTDOWN_PENDING: | |
894 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
895 | /* | |
896 | * RFC 2960 6.1 Transmission of DATA Chunks | |
897 | * | |
898 | * C) When the time comes for the sender to transmit, | |
899 | * before sending new DATA chunks, the sender MUST | |
900 | * first transmit any outstanding DATA chunks which | |
901 | * are marked for retransmission (limited by the | |
902 | * current cwnd). | |
903 | */ | |
904 | if (!list_empty(&q->retransmit)) { | |
f207c050 MH |
905 | if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED) |
906 | goto sctp_flush_out; | |
1da177e4 LT |
907 | if (transport == asoc->peer.retran_path) |
908 | goto retran; | |
909 | ||
910 | /* Switch transports & prepare the packet. */ | |
911 | ||
912 | transport = asoc->peer.retran_path; | |
913 | ||
914 | if (list_empty(&transport->send_ready)) { | |
915 | list_add_tail(&transport->send_ready, | |
916 | &transport_list); | |
917 | } | |
918 | ||
919 | packet = &transport->packet; | |
920 | sctp_packet_config(packet, vtag, | |
921 | asoc->peer.ecn_capable); | |
922 | retran: | |
923 | error = sctp_outq_flush_rtx(q, packet, | |
924 | rtx_timeout, &start_timer); | |
925 | ||
926 | if (start_timer) | |
d9efc223 | 927 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
928 | |
929 | /* This can happen on COOKIE-ECHO resend. Only | |
930 | * one chunk can get bundled with a COOKIE-ECHO. | |
931 | */ | |
932 | if (packet->has_cookie_echo) | |
933 | goto sctp_flush_out; | |
934 | ||
935 | /* Don't send new data if there is still data | |
936 | * waiting to retransmit. | |
937 | */ | |
938 | if (!list_empty(&q->retransmit)) | |
939 | goto sctp_flush_out; | |
940 | } | |
941 | ||
46d5a808 VY |
942 | /* Apply Max.Burst limitation to the current transport in |
943 | * case it will be used for new data. We are going to | |
944 | * rest it before we return, but we want to apply the limit | |
945 | * to the currently queued data. | |
946 | */ | |
947 | if (transport) | |
948 | sctp_transport_burst_limited(transport); | |
949 | ||
1da177e4 | 950 | /* Finally, transmit new packets. */ |
1da177e4 LT |
951 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
952 | /* RFC 2960 6.5 Every DATA chunk MUST carry a valid | |
953 | * stream identifier. | |
954 | */ | |
955 | if (chunk->sinfo.sinfo_stream >= | |
956 | asoc->c.sinit_num_ostreams) { | |
957 | ||
958 | /* Mark as failed send. */ | |
959 | sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); | |
960 | sctp_chunk_free(chunk); | |
961 | continue; | |
962 | } | |
963 | ||
964 | /* Has this chunk expired? */ | |
965 | if (sctp_chunk_abandoned(chunk)) { | |
966 | sctp_chunk_fail(chunk, 0); | |
967 | sctp_chunk_free(chunk); | |
968 | continue; | |
969 | } | |
970 | ||
971 | /* If there is a specified transport, use it. | |
972 | * Otherwise, we want to use the active path. | |
973 | */ | |
974 | new_transport = chunk->transport; | |
3f7a87d2 | 975 | if (!new_transport || |
ad8fec17 | 976 | ((new_transport->state == SCTP_INACTIVE) || |
5aa93bcf NH |
977 | (new_transport->state == SCTP_UNCONFIRMED) || |
978 | (new_transport->state == SCTP_PF))) | |
1da177e4 | 979 | new_transport = asoc->peer.active_path; |
f207c050 MH |
980 | if (new_transport->state == SCTP_UNCONFIRMED) |
981 | continue; | |
1da177e4 LT |
982 | |
983 | /* Change packets if necessary. */ | |
984 | if (new_transport != transport) { | |
985 | transport = new_transport; | |
986 | ||
987 | /* Schedule to have this transport's | |
988 | * packet flushed. | |
989 | */ | |
990 | if (list_empty(&transport->send_ready)) { | |
991 | list_add_tail(&transport->send_ready, | |
992 | &transport_list); | |
993 | } | |
994 | ||
995 | packet = &transport->packet; | |
996 | sctp_packet_config(packet, vtag, | |
997 | asoc->peer.ecn_capable); | |
46d5a808 VY |
998 | /* We've switched transports, so apply the |
999 | * Burst limit to the new transport. | |
1000 | */ | |
1001 | sctp_transport_burst_limited(transport); | |
1da177e4 LT |
1002 | } |
1003 | ||
bb33381d DB |
1004 | pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p " |
1005 | "skb->users:%d\n", | |
1006 | __func__, q, chunk, chunk && chunk->chunk_hdr ? | |
1007 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
1008 | "illegal chunk", ntohl(chunk->subh.data_hdr->tsn), | |
1009 | chunk->skb ? chunk->skb->head : NULL, chunk->skb ? | |
1010 | atomic_read(&chunk->skb->users) : -1); | |
1da177e4 LT |
1011 | |
1012 | /* Add the chunk to the packet. */ | |
2e3216cd | 1013 | status = sctp_packet_transmit_chunk(packet, chunk, 0); |
1da177e4 LT |
1014 | |
1015 | switch (status) { | |
1016 | case SCTP_XMIT_PMTU_FULL: | |
1017 | case SCTP_XMIT_RWND_FULL: | |
526cbef7 | 1018 | case SCTP_XMIT_DELAY: |
1da177e4 LT |
1019 | /* We could not append this chunk, so put |
1020 | * the chunk back on the output queue. | |
1021 | */ | |
bb33381d DB |
1022 | pr_debug("%s: could not transmit tsn:0x%x, status:%d\n", |
1023 | __func__, ntohl(chunk->subh.data_hdr->tsn), | |
1024 | status); | |
1025 | ||
1da177e4 LT |
1026 | sctp_outq_head_data(q, chunk); |
1027 | goto sctp_flush_out; | |
1da177e4 LT |
1028 | |
1029 | case SCTP_XMIT_OK: | |
b93d6471 WY |
1030 | /* The sender is in the SHUTDOWN-PENDING state, |
1031 | * The sender MAY set the I-bit in the DATA | |
1032 | * chunk header. | |
1033 | */ | |
1034 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) | |
1035 | chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; | |
196d6759 MB |
1036 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) |
1037 | asoc->stats.ouodchunks++; | |
1038 | else | |
1039 | asoc->stats.oodchunks++; | |
b93d6471 | 1040 | |
1da177e4 LT |
1041 | break; |
1042 | ||
1043 | default: | |
1044 | BUG(); | |
1045 | } | |
1046 | ||
d808ad9a | 1047 | /* BUG: We assume that the sctp_packet_transmit() |
1da177e4 LT |
1048 | * call below will succeed all the time and add the |
1049 | * chunk to the transmitted list and restart the | |
1050 | * timers. | |
1051 | * It is possible that the call can fail under OOM | |
1052 | * conditions. | |
1053 | * | |
1054 | * Is this really a problem? Won't this behave | |
1055 | * like a lost TSN? | |
1056 | */ | |
1057 | list_add_tail(&chunk->transmitted_list, | |
1058 | &transport->transmitted); | |
1059 | ||
d9efc223 | 1060 | sctp_transport_reset_timers(transport); |
1da177e4 | 1061 | |
1da177e4 LT |
1062 | /* Only let one DATA chunk get bundled with a |
1063 | * COOKIE-ECHO chunk. | |
1064 | */ | |
1065 | if (packet->has_cookie_echo) | |
1066 | goto sctp_flush_out; | |
1067 | } | |
1068 | break; | |
1069 | ||
1070 | default: | |
1071 | /* Do nothing. */ | |
1072 | break; | |
1073 | } | |
1074 | ||
1075 | sctp_flush_out: | |
1076 | ||
1077 | /* Before returning, examine all the transports touched in | |
1078 | * this call. Right now, we bluntly force clear all the | |
1079 | * transports. Things might change after we implement Nagle. | |
1080 | * But such an examination is still required. | |
1081 | * | |
1082 | * --xguo | |
1083 | */ | |
cb3f837b | 1084 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL) { |
1da177e4 LT |
1085 | struct sctp_transport *t = list_entry(ltransport, |
1086 | struct sctp_transport, | |
1087 | send_ready); | |
1088 | packet = &t->packet; | |
1089 | if (!sctp_packet_empty(packet)) | |
1090 | error = sctp_packet_transmit(packet); | |
46d5a808 VY |
1091 | |
1092 | /* Clear the burst limited state, if any */ | |
1093 | sctp_transport_burst_reset(t); | |
1da177e4 LT |
1094 | } |
1095 | ||
1096 | return error; | |
1097 | } | |
1098 | ||
1099 | /* Update unack_data based on the incoming SACK chunk */ | |
1100 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
1101 | struct sctp_sackhdr *sack) | |
1102 | { | |
1103 | sctp_sack_variable_t *frags; | |
1104 | __u16 unack_data; | |
1105 | int i; | |
1106 | ||
1107 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
1108 | ||
1109 | frags = sack->variable; | |
1110 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
1111 | unack_data -= ((ntohs(frags[i].gab.end) - | |
1112 | ntohs(frags[i].gab.start) + 1)); | |
1113 | } | |
1114 | ||
1115 | assoc->unack_data = unack_data; | |
1116 | } | |
1117 | ||
1da177e4 LT |
1118 | /* This is where we REALLY process a SACK. |
1119 | * | |
1120 | * Process the SACK against the outqueue. Mostly, this just frees | |
1121 | * things off the transmitted queue. | |
1122 | */ | |
edfee033 | 1123 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk) |
1da177e4 LT |
1124 | { |
1125 | struct sctp_association *asoc = q->asoc; | |
edfee033 | 1126 | struct sctp_sackhdr *sack = chunk->subh.sack_hdr; |
1da177e4 LT |
1127 | struct sctp_transport *transport; |
1128 | struct sctp_chunk *tchunk = NULL; | |
9dbc15f0 | 1129 | struct list_head *lchunk, *transport_list, *temp; |
1da177e4 LT |
1130 | sctp_sack_variable_t *frags = sack->variable; |
1131 | __u32 sack_ctsn, ctsn, tsn; | |
1132 | __u32 highest_tsn, highest_new_tsn; | |
1133 | __u32 sack_a_rwnd; | |
95c96174 | 1134 | unsigned int outstanding; |
1da177e4 LT |
1135 | struct sctp_transport *primary = asoc->peer.primary_path; |
1136 | int count_of_newacks = 0; | |
2cd9b822 | 1137 | int gap_ack_blocks; |
ea862c8d | 1138 | u8 accum_moved = 0; |
1da177e4 LT |
1139 | |
1140 | /* Grab the association's destination address list. */ | |
1141 | transport_list = &asoc->peer.transport_addr_list; | |
1142 | ||
1143 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
2cd9b822 | 1144 | gap_ack_blocks = ntohs(sack->num_gap_ack_blocks); |
196d6759 | 1145 | asoc->stats.gapcnt += gap_ack_blocks; |
1da177e4 LT |
1146 | /* |
1147 | * SFR-CACC algorithm: | |
1148 | * On receipt of a SACK the sender SHOULD execute the | |
1149 | * following statements. | |
1150 | * | |
1151 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1152 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1153 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1154 | * all destinations. | |
1da177e4 LT |
1155 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
1156 | * is set the receiver of the SACK MUST take the following actions: | |
1157 | * | |
1158 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1159 | * addresses. | |
ab5216a5 VY |
1160 | * |
1161 | * Only bother if changeover_active is set. Otherwise, this is | |
1162 | * totally suboptimal to do on every SACK. | |
1da177e4 | 1163 | */ |
ab5216a5 VY |
1164 | if (primary->cacc.changeover_active) { |
1165 | u8 clear_cycling = 0; | |
1166 | ||
1167 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1168 | primary->cacc.changeover_active = 0; | |
1169 | clear_cycling = 1; | |
1170 | } | |
1171 | ||
1172 | if (clear_cycling || gap_ack_blocks) { | |
1173 | list_for_each_entry(transport, transport_list, | |
1174 | transports) { | |
1175 | if (clear_cycling) | |
1176 | transport->cacc.cycling_changeover = 0; | |
1177 | if (gap_ack_blocks) | |
1178 | transport->cacc.cacc_saw_newack = 0; | |
1179 | } | |
1da177e4 LT |
1180 | } |
1181 | } | |
1182 | ||
1183 | /* Get the highest TSN in the sack. */ | |
1184 | highest_tsn = sack_ctsn; | |
2cd9b822 VY |
1185 | if (gap_ack_blocks) |
1186 | highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); | |
1da177e4 | 1187 | |
bfa0d984 | 1188 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) |
1da177e4 | 1189 | asoc->highest_sacked = highest_tsn; |
1da177e4 | 1190 | |
bfa0d984 | 1191 | highest_new_tsn = sack_ctsn; |
2cd9b822 | 1192 | |
1da177e4 LT |
1193 | /* Run through the retransmit queue. Credit bytes received |
1194 | * and free those chunks that we can. | |
1195 | */ | |
edfee033 | 1196 | sctp_check_transmitted(q, &q->retransmit, NULL, NULL, sack, &highest_new_tsn); |
1da177e4 LT |
1197 | |
1198 | /* Run through the transmitted queue. | |
1199 | * Credit bytes received and free those chunks which we can. | |
1200 | * | |
1201 | * This is a MASSIVE candidate for optimization. | |
1202 | */ | |
9dbc15f0 | 1203 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 | 1204 | sctp_check_transmitted(q, &transport->transmitted, |
edfee033 ND |
1205 | transport, &chunk->source, sack, |
1206 | &highest_new_tsn); | |
1da177e4 LT |
1207 | /* |
1208 | * SFR-CACC algorithm: | |
1209 | * C) Let count_of_newacks be the number of | |
1210 | * destinations for which cacc_saw_newack is set. | |
1211 | */ | |
1212 | if (transport->cacc.cacc_saw_newack) | |
cb3f837b | 1213 | count_of_newacks++; |
1da177e4 LT |
1214 | } |
1215 | ||
ea862c8d VY |
1216 | /* Move the Cumulative TSN Ack Point if appropriate. */ |
1217 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) { | |
1218 | asoc->ctsn_ack_point = sack_ctsn; | |
1219 | accum_moved = 1; | |
1220 | } | |
1221 | ||
2cd9b822 | 1222 | if (gap_ack_blocks) { |
ea862c8d VY |
1223 | |
1224 | if (asoc->fast_recovery && accum_moved) | |
1225 | highest_new_tsn = highest_tsn; | |
1226 | ||
2cd9b822 VY |
1227 | list_for_each_entry(transport, transport_list, transports) |
1228 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1229 | highest_new_tsn, count_of_newacks); | |
1da177e4 LT |
1230 | } |
1231 | ||
1da177e4 LT |
1232 | /* Update unack_data field in the assoc. */ |
1233 | sctp_sack_update_unack_data(asoc, sack); | |
1234 | ||
1235 | ctsn = asoc->ctsn_ack_point; | |
1236 | ||
1237 | /* Throw away stuff rotting on the sack queue. */ | |
1238 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1239 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1240 | transmitted_list); | |
1241 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
5f9646c3 VY |
1242 | if (TSN_lte(tsn, ctsn)) { |
1243 | list_del_init(&tchunk->transmitted_list); | |
1da177e4 | 1244 | sctp_chunk_free(tchunk); |
5f9646c3 | 1245 | } |
1da177e4 LT |
1246 | } |
1247 | ||
1248 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1249 | * number of bytes still outstanding after processing the | |
1250 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1251 | */ | |
1252 | ||
1253 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
1254 | outstanding = q->outstanding_bytes; | |
1255 | ||
1256 | if (outstanding < sack_a_rwnd) | |
1257 | sack_a_rwnd -= outstanding; | |
1258 | else | |
1259 | sack_a_rwnd = 0; | |
1260 | ||
1261 | asoc->peer.rwnd = sack_a_rwnd; | |
1262 | ||
1263 | sctp_generate_fwdtsn(q, sack_ctsn); | |
1264 | ||
bb33381d DB |
1265 | pr_debug("%s: sack cumulative tsn ack:0x%x\n", __func__, sack_ctsn); |
1266 | pr_debug("%s: cumulative tsn ack of assoc:%p is 0x%x, " | |
1267 | "advertised peer ack point:0x%x\n", __func__, asoc, ctsn, | |
1268 | asoc->adv_peer_ack_point); | |
1da177e4 | 1269 | |
619a60ee | 1270 | return sctp_outq_is_empty(q); |
1da177e4 LT |
1271 | } |
1272 | ||
619a60ee VY |
1273 | /* Is the outqueue empty? |
1274 | * The queue is empty when we have not pending data, no in-flight data | |
1275 | * and nothing pending retransmissions. | |
1276 | */ | |
1da177e4 LT |
1277 | int sctp_outq_is_empty(const struct sctp_outq *q) |
1278 | { | |
619a60ee VY |
1279 | return q->out_qlen == 0 && q->outstanding_bytes == 0 && |
1280 | list_empty(&q->retransmit); | |
1da177e4 LT |
1281 | } |
1282 | ||
1283 | /******************************************************************** | |
1284 | * 2nd Level Abstractions | |
1285 | ********************************************************************/ | |
1286 | ||
1287 | /* Go through a transport's transmitted list or the association's retransmit | |
1288 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1289 | * The retransmit list will not have an associated transport. | |
1290 | * | |
1291 | * I added coherent debug information output. --xguo | |
1292 | * | |
1293 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1294 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1295 | * KEPT TSN6-TSN7, etc. | |
1296 | */ | |
1297 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1298 | struct list_head *transmitted_queue, | |
1299 | struct sctp_transport *transport, | |
edfee033 | 1300 | union sctp_addr *saddr, |
1da177e4 | 1301 | struct sctp_sackhdr *sack, |
bfa0d984 | 1302 | __u32 *highest_new_tsn_in_sack) |
1da177e4 LT |
1303 | { |
1304 | struct list_head *lchunk; | |
1305 | struct sctp_chunk *tchunk; | |
1306 | struct list_head tlist; | |
1307 | __u32 tsn; | |
1308 | __u32 sack_ctsn; | |
1309 | __u32 rtt; | |
1310 | __u8 restart_timer = 0; | |
1311 | int bytes_acked = 0; | |
31b02e15 | 1312 | int migrate_bytes = 0; |
8c2f414a | 1313 | bool forward_progress = false; |
1da177e4 | 1314 | |
1da177e4 LT |
1315 | sack_ctsn = ntohl(sack->cum_tsn_ack); |
1316 | ||
1317 | INIT_LIST_HEAD(&tlist); | |
1318 | ||
1319 | /* The while loop will skip empty transmitted queues. */ | |
1320 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1321 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1322 | transmitted_list); | |
1323 | ||
1324 | if (sctp_chunk_abandoned(tchunk)) { | |
1325 | /* Move the chunk to abandoned list. */ | |
1326 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
1327 | |
1328 | /* If this chunk has not been acked, stop | |
1329 | * considering it as 'outstanding'. | |
1330 | */ | |
1331 | if (!tchunk->tsn_gap_acked) { | |
31b02e15 VY |
1332 | if (tchunk->transport) |
1333 | tchunk->transport->flight_size -= | |
1334 | sctp_data_size(tchunk); | |
8c4a2d41 VY |
1335 | q->outstanding_bytes -= sctp_data_size(tchunk); |
1336 | } | |
1da177e4 LT |
1337 | continue; |
1338 | } | |
1339 | ||
1340 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1341 | if (sctp_acked(sack, tsn)) { | |
1342 | /* If this queue is the retransmit queue, the | |
1343 | * retransmit timer has already reclaimed | |
1344 | * the outstanding bytes for this chunk, so only | |
1345 | * count bytes associated with a transport. | |
1346 | */ | |
1347 | if (transport) { | |
1348 | /* If this chunk is being used for RTT | |
1349 | * measurement, calculate the RTT and update | |
1350 | * the RTO using this value. | |
1351 | * | |
1352 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1353 | * MUST NOT be made using packets that were | |
1354 | * retransmitted (and thus for which it is | |
1355 | * ambiguous whether the reply was for the | |
1356 | * first instance of the packet or a later | |
1357 | * instance). | |
1358 | */ | |
d808ad9a | 1359 | if (!tchunk->tsn_gap_acked && |
6eabca54 | 1360 | !tchunk->resent && |
1da177e4 | 1361 | tchunk->rtt_in_progress) { |
4c9f5d53 | 1362 | tchunk->rtt_in_progress = 0; |
1da177e4 LT |
1363 | rtt = jiffies - tchunk->sent_at; |
1364 | sctp_transport_update_rto(transport, | |
1365 | rtt); | |
1366 | } | |
1367 | } | |
31b02e15 VY |
1368 | |
1369 | /* If the chunk hasn't been marked as ACKED, | |
1370 | * mark it and account bytes_acked if the | |
1371 | * chunk had a valid transport (it will not | |
1372 | * have a transport if ASCONF had deleted it | |
1373 | * while DATA was outstanding). | |
1374 | */ | |
1375 | if (!tchunk->tsn_gap_acked) { | |
1376 | tchunk->tsn_gap_acked = 1; | |
d6c41614 CX |
1377 | if (TSN_lt(*highest_new_tsn_in_sack, tsn)) |
1378 | *highest_new_tsn_in_sack = tsn; | |
31b02e15 VY |
1379 | bytes_acked += sctp_data_size(tchunk); |
1380 | if (!tchunk->transport) | |
1381 | migrate_bytes += sctp_data_size(tchunk); | |
8c2f414a | 1382 | forward_progress = true; |
31b02e15 VY |
1383 | } |
1384 | ||
d808ad9a | 1385 | if (TSN_lte(tsn, sack_ctsn)) { |
1da177e4 LT |
1386 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
1387 | * | |
1388 | * R3) Whenever a SACK is received | |
1389 | * that acknowledges the DATA chunk | |
1390 | * with the earliest outstanding TSN | |
1391 | * for that address, restart T3-rtx | |
1392 | * timer for that address with its | |
1393 | * current RTO. | |
1394 | */ | |
1395 | restart_timer = 1; | |
8c2f414a | 1396 | forward_progress = true; |
1da177e4 LT |
1397 | |
1398 | if (!tchunk->tsn_gap_acked) { | |
1da177e4 LT |
1399 | /* |
1400 | * SFR-CACC algorithm: | |
1401 | * 2) If the SACK contains gap acks | |
1402 | * and the flag CHANGEOVER_ACTIVE is | |
1403 | * set the receiver of the SACK MUST | |
1404 | * take the following action: | |
1405 | * | |
1406 | * B) For each TSN t being acked that | |
1407 | * has not been acked in any SACK so | |
1408 | * far, set cacc_saw_newack to 1 for | |
1409 | * the destination that the TSN was | |
1410 | * sent to. | |
1411 | */ | |
1412 | if (transport && | |
1413 | sack->num_gap_ack_blocks && | |
1414 | q->asoc->peer.primary_path->cacc. | |
1415 | changeover_active) | |
1416 | transport->cacc.cacc_saw_newack | |
1417 | = 1; | |
1418 | } | |
1419 | ||
1420 | list_add_tail(&tchunk->transmitted_list, | |
1421 | &q->sacked); | |
1422 | } else { | |
1423 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1424 | * M2) Each time a SACK arrives reporting | |
1425 | * 'Stray DATA chunk(s)' record the highest TSN | |
1426 | * reported as newly acknowledged, call this | |
1427 | * value 'HighestTSNinSack'. A newly | |
1428 | * acknowledged DATA chunk is one not | |
1429 | * previously acknowledged in a SACK. | |
1430 | * | |
1431 | * When the SCTP sender of data receives a SACK | |
1432 | * chunk that acknowledges, for the first time, | |
1433 | * the receipt of a DATA chunk, all the still | |
1434 | * unacknowledged DATA chunks whose TSN is | |
1435 | * older than that newly acknowledged DATA | |
1436 | * chunk, are qualified as 'Stray DATA chunks'. | |
1437 | */ | |
1da177e4 LT |
1438 | list_add_tail(lchunk, &tlist); |
1439 | } | |
1da177e4 LT |
1440 | } else { |
1441 | if (tchunk->tsn_gap_acked) { | |
bb33381d DB |
1442 | pr_debug("%s: receiver reneged on data TSN:0x%x\n", |
1443 | __func__, tsn); | |
1444 | ||
1da177e4 LT |
1445 | tchunk->tsn_gap_acked = 0; |
1446 | ||
31b02e15 VY |
1447 | if (tchunk->transport) |
1448 | bytes_acked -= sctp_data_size(tchunk); | |
1da177e4 LT |
1449 | |
1450 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1451 | * | |
1452 | * R4) Whenever a SACK is received missing a | |
1453 | * TSN that was previously acknowledged via a | |
1454 | * Gap Ack Block, start T3-rtx for the | |
1455 | * destination address to which the DATA | |
1456 | * chunk was originally | |
1457 | * transmitted if it is not already running. | |
1458 | */ | |
1459 | restart_timer = 1; | |
1460 | } | |
1461 | ||
1462 | list_add_tail(lchunk, &tlist); | |
1da177e4 LT |
1463 | } |
1464 | } | |
1465 | ||
1da177e4 LT |
1466 | if (transport) { |
1467 | if (bytes_acked) { | |
f8d96052 TG |
1468 | struct sctp_association *asoc = transport->asoc; |
1469 | ||
31b02e15 VY |
1470 | /* We may have counted DATA that was migrated |
1471 | * to this transport due to DEL-IP operation. | |
1472 | * Subtract those bytes, since the were never | |
1473 | * send on this transport and shouldn't be | |
1474 | * credited to this transport. | |
1475 | */ | |
1476 | bytes_acked -= migrate_bytes; | |
1477 | ||
1da177e4 LT |
1478 | /* 8.2. When an outstanding TSN is acknowledged, |
1479 | * the endpoint shall clear the error counter of | |
1480 | * the destination transport address to which the | |
1481 | * DATA chunk was last sent. | |
1482 | * The association's overall error counter is | |
1483 | * also cleared. | |
1484 | */ | |
1485 | transport->error_count = 0; | |
1486 | transport->asoc->overall_error_count = 0; | |
8c2f414a | 1487 | forward_progress = true; |
1da177e4 | 1488 | |
f8d96052 TG |
1489 | /* |
1490 | * While in SHUTDOWN PENDING, we may have started | |
1491 | * the T5 shutdown guard timer after reaching the | |
1492 | * retransmission limit. Stop that timer as soon | |
1493 | * as the receiver acknowledged any data. | |
1494 | */ | |
1495 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING && | |
1496 | del_timer(&asoc->timers | |
1497 | [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD])) | |
1498 | sctp_association_put(asoc); | |
1499 | ||
1da177e4 LT |
1500 | /* Mark the destination transport address as |
1501 | * active if it is not so marked. | |
1502 | */ | |
edfee033 ND |
1503 | if ((transport->state == SCTP_INACTIVE || |
1504 | transport->state == SCTP_UNCONFIRMED) && | |
1505 | sctp_cmp_addr_exact(&transport->ipaddr, saddr)) { | |
1da177e4 LT |
1506 | sctp_assoc_control_transport( |
1507 | transport->asoc, | |
1508 | transport, | |
1509 | SCTP_TRANSPORT_UP, | |
1510 | SCTP_RECEIVED_SACK); | |
1511 | } | |
1512 | ||
1513 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1514 | bytes_acked); | |
1515 | ||
1516 | transport->flight_size -= bytes_acked; | |
8b73a07c GJ |
1517 | if (transport->flight_size == 0) |
1518 | transport->partial_bytes_acked = 0; | |
31b02e15 | 1519 | q->outstanding_bytes -= bytes_acked + migrate_bytes; |
1da177e4 LT |
1520 | } else { |
1521 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1522 | * When a sender is doing zero window probing, it | |
1523 | * should not timeout the association if it continues | |
1524 | * to receive new packets from the receiver. The | |
1525 | * reason is that the receiver MAY keep its window | |
1526 | * closed for an indefinite time. | |
1527 | * A sender is doing zero window probing when the | |
1528 | * receiver's advertised window is zero, and there is | |
1529 | * only one data chunk in flight to the receiver. | |
f8d96052 TG |
1530 | * |
1531 | * Allow the association to timeout while in SHUTDOWN | |
1532 | * PENDING or SHUTDOWN RECEIVED in case the receiver | |
1533 | * stays in zero window mode forever. | |
1da177e4 LT |
1534 | */ |
1535 | if (!q->asoc->peer.rwnd && | |
1536 | !list_empty(&tlist) && | |
f8d96052 TG |
1537 | (sack_ctsn+2 == q->asoc->next_tsn) && |
1538 | q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) { | |
bb33381d DB |
1539 | pr_debug("%s: sack received for zero window " |
1540 | "probe:%u\n", __func__, sack_ctsn); | |
1541 | ||
1da177e4 LT |
1542 | q->asoc->overall_error_count = 0; |
1543 | transport->error_count = 0; | |
1544 | } | |
1545 | } | |
1546 | ||
1547 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1548 | * | |
1549 | * R2) Whenever all outstanding data sent to an address have | |
1550 | * been acknowledged, turn off the T3-rtx timer of that | |
1551 | * address. | |
1552 | */ | |
1553 | if (!transport->flight_size) { | |
25cc4ae9 | 1554 | if (del_timer(&transport->T3_rtx_timer)) |
1da177e4 | 1555 | sctp_transport_put(transport); |
1da177e4 LT |
1556 | } else if (restart_timer) { |
1557 | if (!mod_timer(&transport->T3_rtx_timer, | |
1558 | jiffies + transport->rto)) | |
1559 | sctp_transport_hold(transport); | |
1560 | } | |
8c2f414a DB |
1561 | |
1562 | if (forward_progress) { | |
1563 | if (transport->dst) | |
1564 | dst_confirm(transport->dst); | |
1565 | } | |
1da177e4 LT |
1566 | } |
1567 | ||
1568 | list_splice(&tlist, transmitted_queue); | |
1569 | } | |
1570 | ||
1571 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1572 | static void sctp_mark_missing(struct sctp_outq *q, | |
1573 | struct list_head *transmitted_queue, | |
1574 | struct sctp_transport *transport, | |
1575 | __u32 highest_new_tsn_in_sack, | |
1576 | int count_of_newacks) | |
1577 | { | |
1578 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1579 | __u32 tsn; |
1580 | char do_fast_retransmit = 0; | |
ea862c8d VY |
1581 | struct sctp_association *asoc = q->asoc; |
1582 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1da177e4 | 1583 | |
9dbc15f0 | 1584 | list_for_each_entry(chunk, transmitted_queue, transmitted_list) { |
1da177e4 | 1585 | |
1da177e4 LT |
1586 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1587 | ||
1588 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1589 | * 'Unacknowledged TSN's', if the TSN number of an | |
1590 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1591 | * value, increment the 'TSN.Missing.Report' count on that | |
1592 | * chunk if it has NOT been fast retransmitted or marked for | |
1593 | * fast retransmit already. | |
1594 | */ | |
c226ef9b | 1595 | if (chunk->fast_retransmit == SCTP_CAN_FRTX && |
1da177e4 LT |
1596 | !chunk->tsn_gap_acked && |
1597 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1598 | ||
1599 | /* SFR-CACC may require us to skip marking | |
1600 | * this chunk as missing. | |
1601 | */ | |
f246a7b7 VY |
1602 | if (!transport || !sctp_cacc_skip(primary, |
1603 | chunk->transport, | |
1604 | count_of_newacks, tsn)) { | |
1da177e4 LT |
1605 | chunk->tsn_missing_report++; |
1606 | ||
bb33381d DB |
1607 | pr_debug("%s: tsn:0x%x missing counter:%d\n", |
1608 | __func__, tsn, chunk->tsn_missing_report); | |
1da177e4 LT |
1609 | } |
1610 | } | |
1611 | /* | |
1612 | * M4) If any DATA chunk is found to have a | |
1613 | * 'TSN.Missing.Report' | |
27852c26 | 1614 | * value larger than or equal to 3, mark that chunk for |
1da177e4 LT |
1615 | * retransmission and start the fast retransmit procedure. |
1616 | */ | |
1617 | ||
27852c26 | 1618 | if (chunk->tsn_missing_report >= 3) { |
c226ef9b | 1619 | chunk->fast_retransmit = SCTP_NEED_FRTX; |
1da177e4 LT |
1620 | do_fast_retransmit = 1; |
1621 | } | |
1622 | } | |
1623 | ||
1624 | if (transport) { | |
1625 | if (do_fast_retransmit) | |
1626 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1627 | ||
bb33381d DB |
1628 | pr_debug("%s: transport:%p, cwnd:%d, ssthresh:%d, " |
1629 | "flight_size:%d, pba:%d\n", __func__, transport, | |
1630 | transport->cwnd, transport->ssthresh, | |
1631 | transport->flight_size, transport->partial_bytes_acked); | |
1da177e4 LT |
1632 | } |
1633 | } | |
1634 | ||
1635 | /* Is the given TSN acked by this packet? */ | |
1636 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1637 | { | |
1638 | int i; | |
1639 | sctp_sack_variable_t *frags; | |
1640 | __u16 gap; | |
1641 | __u32 ctsn = ntohl(sack->cum_tsn_ack); | |
1642 | ||
d808ad9a | 1643 | if (TSN_lte(tsn, ctsn)) |
1da177e4 LT |
1644 | goto pass; |
1645 | ||
1646 | /* 3.3.4 Selective Acknowledgement (SACK) (3): | |
1647 | * | |
1648 | * Gap Ack Blocks: | |
1649 | * These fields contain the Gap Ack Blocks. They are repeated | |
1650 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1651 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1652 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1653 | * Ack + Gap Ack Block Start) and less than or equal to | |
1654 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1655 | * Block are assumed to have been received correctly. | |
1656 | */ | |
1657 | ||
1658 | frags = sack->variable; | |
1659 | gap = tsn - ctsn; | |
1660 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { | |
1661 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && | |
1662 | TSN_lte(gap, ntohs(frags[i].gab.end))) | |
1663 | goto pass; | |
1664 | } | |
1665 | ||
1666 | return 0; | |
1667 | pass: | |
1668 | return 1; | |
1669 | } | |
1670 | ||
1671 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
9f81bcd9 | 1672 | int nskips, __be16 stream) |
1da177e4 LT |
1673 | { |
1674 | int i; | |
1675 | ||
1676 | for (i = 0; i < nskips; i++) { | |
1677 | if (skiplist[i].stream == stream) | |
1678 | return i; | |
1679 | } | |
1680 | return i; | |
1681 | } | |
1682 | ||
1683 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
1684 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) | |
1685 | { | |
1686 | struct sctp_association *asoc = q->asoc; | |
1687 | struct sctp_chunk *ftsn_chunk = NULL; | |
1688 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1689 | int nskips = 0; | |
1690 | int skip_pos = 0; | |
1691 | __u32 tsn; | |
1692 | struct sctp_chunk *chunk; | |
1693 | struct list_head *lchunk, *temp; | |
1694 | ||
76595024 WY |
1695 | if (!asoc->peer.prsctp_capable) |
1696 | return; | |
1697 | ||
1da177e4 LT |
1698 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
1699 | * received SACK. | |
d808ad9a | 1700 | * |
1da177e4 LT |
1701 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
1702 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1703 | */ | |
1704 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1705 | asoc->adv_peer_ack_point = ctsn; | |
1706 | ||
1707 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1708 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1709 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1710 | * shown in the following example: | |
1711 | * | |
1712 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1713 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
d808ad9a | 1714 | * |
1da177e4 LT |
1715 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
1716 | * normal SACK processing local advancement | |
1717 | * ... ... | |
1718 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1719 | * 103 abandoned 103 abandoned | |
1720 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1721 | * 105 105 | |
1722 | * 106 acked 106 acked | |
1723 | * ... ... | |
1724 | * | |
1725 | * In this example, the data sender successfully advanced the | |
1726 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1727 | */ | |
1728 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1729 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1730 | transmitted_list); | |
1731 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1732 | ||
1733 | /* Remove any chunks in the abandoned queue that are acked by | |
1734 | * the ctsn. | |
d808ad9a | 1735 | */ |
1da177e4 LT |
1736 | if (TSN_lte(tsn, ctsn)) { |
1737 | list_del_init(lchunk); | |
1da177e4 LT |
1738 | sctp_chunk_free(chunk); |
1739 | } else { | |
1740 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1741 | asoc->adv_peer_ack_point = tsn; | |
1742 | if (chunk->chunk_hdr->flags & | |
1743 | SCTP_DATA_UNORDERED) | |
1744 | continue; | |
1745 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1746 | nskips, | |
1747 | chunk->subh.data_hdr->stream); | |
1748 | ftsn_skip_arr[skip_pos].stream = | |
1749 | chunk->subh.data_hdr->stream; | |
1750 | ftsn_skip_arr[skip_pos].ssn = | |
1751 | chunk->subh.data_hdr->ssn; | |
1752 | if (skip_pos == nskips) | |
1753 | nskips++; | |
1754 | if (nskips == 10) | |
1755 | break; | |
1756 | } else | |
1757 | break; | |
1758 | } | |
1759 | } | |
1760 | ||
1761 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1762 | * is greater than the Cumulative TSN ACK carried in the received | |
1763 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1764 | * chunk containing the latest value of the | |
1765 | * "Advanced.Peer.Ack.Point". | |
1766 | * | |
1767 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1768 | * list each stream and sequence number in the forwarded TSN. This | |
1769 | * information will enable the receiver to easily find any | |
1770 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1771 | * SHOULD only be reported once; this means that if multiple | |
1772 | * abandoned messages occur in the same stream then only the | |
1773 | * highest abandoned stream sequence number is reported. If the | |
1774 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1775 | * the sender of the FORWARD TSN SHOULD lower the | |
1776 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1777 | * single MTU. | |
1778 | */ | |
1779 | if (asoc->adv_peer_ack_point > ctsn) | |
1780 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
d808ad9a | 1781 | nskips, &ftsn_skip_arr[0]); |
1da177e4 LT |
1782 | |
1783 | if (ftsn_chunk) { | |
79af02c2 | 1784 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
b01a2407 | 1785 | SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
1786 | } |
1787 | } |