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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 | ||
cea8768f | 71 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp); |
abd0b198 | 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. */ | |
cea8768f | 288 | int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk, gfp_t gfp) |
1da177e4 | 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 | 326 | |
69b5777f | 327 | sctp_chunk_hold(chunk); |
1da177e4 LT |
328 | sctp_outq_tail_data(q, chunk); |
329 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
b01a2407 | 330 | SCTP_INC_STATS(net, SCTP_MIB_OUTUNORDERCHUNKS); |
1da177e4 | 331 | else |
b01a2407 | 332 | SCTP_INC_STATS(net, SCTP_MIB_OUTORDERCHUNKS); |
1da177e4 | 333 | break; |
3ff50b79 | 334 | } |
1da177e4 | 335 | } else { |
79af02c2 | 336 | list_add_tail(&chunk->list, &q->control_chunk_list); |
b01a2407 | 337 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
338 | } |
339 | ||
340 | if (error < 0) | |
341 | return error; | |
342 | ||
343 | if (!q->cork) | |
cea8768f | 344 | error = sctp_outq_flush(q, 0, gfp); |
1da177e4 LT |
345 | |
346 | return error; | |
347 | } | |
348 | ||
349 | /* Insert a chunk into the sorted list based on the TSNs. The retransmit list | |
350 | * and the abandoned list are in ascending order. | |
351 | */ | |
352 | static void sctp_insert_list(struct list_head *head, struct list_head *new) | |
353 | { | |
354 | struct list_head *pos; | |
355 | struct sctp_chunk *nchunk, *lchunk; | |
356 | __u32 ntsn, ltsn; | |
357 | int done = 0; | |
358 | ||
359 | nchunk = list_entry(new, struct sctp_chunk, transmitted_list); | |
360 | ntsn = ntohl(nchunk->subh.data_hdr->tsn); | |
361 | ||
362 | list_for_each(pos, head) { | |
363 | lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); | |
364 | ltsn = ntohl(lchunk->subh.data_hdr->tsn); | |
365 | if (TSN_lt(ntsn, ltsn)) { | |
366 | list_add(new, pos->prev); | |
367 | done = 1; | |
368 | break; | |
369 | } | |
370 | } | |
371 | if (!done) | |
d808ad9a | 372 | list_add_tail(new, head); |
1da177e4 LT |
373 | } |
374 | ||
375 | /* Mark all the eligible packets on a transport for retransmission. */ | |
376 | void sctp_retransmit_mark(struct sctp_outq *q, | |
377 | struct sctp_transport *transport, | |
b6157d8e | 378 | __u8 reason) |
1da177e4 LT |
379 | { |
380 | struct list_head *lchunk, *ltemp; | |
381 | struct sctp_chunk *chunk; | |
382 | ||
383 | /* Walk through the specified transmitted queue. */ | |
384 | list_for_each_safe(lchunk, ltemp, &transport->transmitted) { | |
385 | chunk = list_entry(lchunk, struct sctp_chunk, | |
386 | transmitted_list); | |
387 | ||
388 | /* If the chunk is abandoned, move it to abandoned list. */ | |
389 | if (sctp_chunk_abandoned(chunk)) { | |
390 | list_del_init(lchunk); | |
391 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
392 | |
393 | /* If this chunk has not been previousely acked, | |
394 | * stop considering it 'outstanding'. Our peer | |
395 | * will most likely never see it since it will | |
396 | * not be retransmitted | |
397 | */ | |
398 | if (!chunk->tsn_gap_acked) { | |
31b02e15 VY |
399 | if (chunk->transport) |
400 | chunk->transport->flight_size -= | |
401 | sctp_data_size(chunk); | |
8c4a2d41 | 402 | q->outstanding_bytes -= sctp_data_size(chunk); |
a76c0adf | 403 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
8c4a2d41 | 404 | } |
1da177e4 LT |
405 | continue; |
406 | } | |
407 | ||
b6157d8e VY |
408 | /* If we are doing retransmission due to a timeout or pmtu |
409 | * discovery, only the chunks that are not yet acked should | |
410 | * be added to the retransmit queue. | |
1da177e4 | 411 | */ |
b6157d8e | 412 | if ((reason == SCTP_RTXR_FAST_RTX && |
c226ef9b | 413 | (chunk->fast_retransmit == SCTP_NEED_FRTX)) || |
b6157d8e | 414 | (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) { |
1da177e4 LT |
415 | /* RFC 2960 6.2.1 Processing a Received SACK |
416 | * | |
417 | * C) Any time a DATA chunk is marked for | |
418 | * retransmission (via either T3-rtx timer expiration | |
419 | * (Section 6.3.3) or via fast retransmit | |
420 | * (Section 7.2.4)), add the data size of those | |
421 | * chunks to the rwnd. | |
422 | */ | |
a76c0adf | 423 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
1da177e4 | 424 | q->outstanding_bytes -= sctp_data_size(chunk); |
31b02e15 VY |
425 | if (chunk->transport) |
426 | transport->flight_size -= sctp_data_size(chunk); | |
1da177e4 LT |
427 | |
428 | /* sctpimpguide-05 Section 2.8.2 | |
429 | * M5) If a T3-rtx timer expires, the | |
430 | * 'TSN.Missing.Report' of all affected TSNs is set | |
431 | * to 0. | |
432 | */ | |
433 | chunk->tsn_missing_report = 0; | |
434 | ||
435 | /* If a chunk that is being used for RTT measurement | |
436 | * has to be retransmitted, we cannot use this chunk | |
437 | * anymore for RTT measurements. Reset rto_pending so | |
438 | * that a new RTT measurement is started when a new | |
439 | * data chunk is sent. | |
440 | */ | |
441 | if (chunk->rtt_in_progress) { | |
442 | chunk->rtt_in_progress = 0; | |
443 | transport->rto_pending = 0; | |
444 | } | |
445 | ||
6eabca54 XZ |
446 | chunk->resent = 1; |
447 | ||
1da177e4 LT |
448 | /* Move the chunk to the retransmit queue. The chunks |
449 | * on the retransmit queue are always kept in order. | |
450 | */ | |
451 | list_del_init(lchunk); | |
452 | sctp_insert_list(&q->retransmit, lchunk); | |
453 | } | |
454 | } | |
455 | ||
bb33381d DB |
456 | pr_debug("%s: transport:%p, reason:%d, cwnd:%d, ssthresh:%d, " |
457 | "flight_size:%d, pba:%d\n", __func__, transport, reason, | |
458 | transport->cwnd, transport->ssthresh, transport->flight_size, | |
459 | transport->partial_bytes_acked); | |
1da177e4 LT |
460 | } |
461 | ||
462 | /* Mark all the eligible packets on a transport for retransmission and force | |
463 | * one packet out. | |
464 | */ | |
465 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, | |
466 | sctp_retransmit_reason_t reason) | |
467 | { | |
b01a2407 | 468 | struct net *net = sock_net(q->asoc->base.sk); |
1da177e4 | 469 | int error = 0; |
1da177e4 | 470 | |
cb3f837b | 471 | switch (reason) { |
1da177e4 | 472 | case SCTP_RTXR_T3_RTX: |
b01a2407 | 473 | SCTP_INC_STATS(net, SCTP_MIB_T3_RETRANSMITS); |
1da177e4 LT |
474 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); |
475 | /* Update the retran path if the T3-rtx timer has expired for | |
476 | * the current retran path. | |
477 | */ | |
478 | if (transport == transport->asoc->peer.retran_path) | |
479 | sctp_assoc_update_retran_path(transport->asoc); | |
58fbbed4 NH |
480 | transport->asoc->rtx_data_chunks += |
481 | transport->asoc->unack_data; | |
1da177e4 LT |
482 | break; |
483 | case SCTP_RTXR_FAST_RTX: | |
b01a2407 | 484 | SCTP_INC_STATS(net, SCTP_MIB_FAST_RETRANSMITS); |
1da177e4 | 485 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); |
62aeaff5 | 486 | q->fast_rtx = 1; |
1da177e4 LT |
487 | break; |
488 | case SCTP_RTXR_PMTUD: | |
b01a2407 | 489 | SCTP_INC_STATS(net, SCTP_MIB_PMTUD_RETRANSMITS); |
1da177e4 | 490 | break; |
b6157d8e | 491 | case SCTP_RTXR_T1_RTX: |
b01a2407 | 492 | SCTP_INC_STATS(net, SCTP_MIB_T1_RETRANSMITS); |
58fbbed4 | 493 | transport->asoc->init_retries++; |
b6157d8e | 494 | break; |
ac0b0462 SS |
495 | default: |
496 | BUG(); | |
1da177e4 LT |
497 | } |
498 | ||
b6157d8e | 499 | sctp_retransmit_mark(q, transport, reason); |
1da177e4 LT |
500 | |
501 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, | |
502 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by | |
503 | * following the procedures outlined in C1 - C5. | |
504 | */ | |
8b750ce5 VY |
505 | if (reason == SCTP_RTXR_T3_RTX) |
506 | sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); | |
1da177e4 | 507 | |
8b750ce5 VY |
508 | /* Flush the queues only on timeout, since fast_rtx is only |
509 | * triggered during sack processing and the queue | |
510 | * will be flushed at the end. | |
511 | */ | |
512 | if (reason != SCTP_RTXR_FAST_RTX) | |
cea8768f | 513 | error = sctp_outq_flush(q, /* rtx_timeout */ 1, GFP_ATOMIC); |
1da177e4 LT |
514 | |
515 | if (error) | |
516 | q->asoc->base.sk->sk_err = -error; | |
517 | } | |
518 | ||
519 | /* | |
520 | * Transmit DATA chunks on the retransmit queue. Upon return from | |
521 | * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which | |
522 | * need to be transmitted by the caller. | |
523 | * We assume that pkt->transport has already been set. | |
524 | * | |
525 | * The return value is a normal kernel error return value. | |
526 | */ | |
527 | static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, | |
528 | int rtx_timeout, int *start_timer) | |
529 | { | |
530 | struct list_head *lqueue; | |
1da177e4 LT |
531 | struct sctp_transport *transport = pkt->transport; |
532 | sctp_xmit_t status; | |
533 | struct sctp_chunk *chunk, *chunk1; | |
62aeaff5 | 534 | int fast_rtx; |
1da177e4 | 535 | int error = 0; |
62aeaff5 | 536 | int timer = 0; |
8b750ce5 | 537 | int done = 0; |
1da177e4 | 538 | |
1da177e4 | 539 | lqueue = &q->retransmit; |
62aeaff5 | 540 | fast_rtx = q->fast_rtx; |
1da177e4 | 541 | |
8b750ce5 VY |
542 | /* This loop handles time-out retransmissions, fast retransmissions, |
543 | * and retransmissions due to opening of whindow. | |
544 | * | |
545 | * RFC 2960 6.3.3 Handle T3-rtx Expiration | |
1da177e4 LT |
546 | * |
547 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
548 | * outstanding DATA chunks for the address for which the | |
549 | * T3-rtx has expired will fit into a single packet, subject | |
550 | * to the MTU constraint for the path corresponding to the | |
551 | * destination transport address to which the retransmission | |
552 | * is being sent (this may be different from the address for | |
553 | * which the timer expires [see Section 6.4]). Call this value | |
554 | * K. Bundle and retransmit those K DATA chunks in a single | |
555 | * packet to the destination endpoint. | |
556 | * | |
557 | * [Just to be painfully clear, if we are retransmitting | |
558 | * because a timeout just happened, we should send only ONE | |
559 | * packet of retransmitted data.] | |
8b750ce5 VY |
560 | * |
561 | * For fast retransmissions we also send only ONE packet. However, | |
562 | * if we are just flushing the queue due to open window, we'll | |
563 | * try to send as much as possible. | |
1da177e4 | 564 | */ |
8b750ce5 | 565 | list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { |
4c6a6f42 WY |
566 | /* If the chunk is abandoned, move it to abandoned list. */ |
567 | if (sctp_chunk_abandoned(chunk)) { | |
568 | list_del_init(&chunk->transmitted_list); | |
569 | sctp_insert_list(&q->abandoned, | |
570 | &chunk->transmitted_list); | |
571 | continue; | |
572 | } | |
1da177e4 LT |
573 | |
574 | /* Make sure that Gap Acked TSNs are not retransmitted. A | |
575 | * simple approach is just to move such TSNs out of the | |
576 | * way and into a 'transmitted' queue and skip to the | |
577 | * next chunk. | |
578 | */ | |
579 | if (chunk->tsn_gap_acked) { | |
54a27924 WY |
580 | list_move_tail(&chunk->transmitted_list, |
581 | &transport->transmitted); | |
1da177e4 LT |
582 | continue; |
583 | } | |
584 | ||
8b750ce5 VY |
585 | /* If we are doing fast retransmit, ignore non-fast_rtransmit |
586 | * chunks | |
587 | */ | |
588 | if (fast_rtx && !chunk->fast_retransmit) | |
589 | continue; | |
590 | ||
bc4f841a | 591 | redo: |
1da177e4 LT |
592 | /* Attempt to append this chunk to the packet. */ |
593 | status = sctp_packet_append_chunk(pkt, chunk); | |
594 | ||
595 | switch (status) { | |
596 | case SCTP_XMIT_PMTU_FULL: | |
bc4f841a WY |
597 | if (!pkt->has_data && !pkt->has_cookie_echo) { |
598 | /* If this packet did not contain DATA then | |
599 | * retransmission did not happen, so do it | |
600 | * again. We'll ignore the error here since | |
601 | * control chunks are already freed so there | |
602 | * is nothing we can do. | |
603 | */ | |
cea8768f | 604 | sctp_packet_transmit(pkt, GFP_ATOMIC); |
bc4f841a WY |
605 | goto redo; |
606 | } | |
607 | ||
1da177e4 | 608 | /* Send this packet. */ |
cea8768f | 609 | error = sctp_packet_transmit(pkt, GFP_ATOMIC); |
1da177e4 LT |
610 | |
611 | /* If we are retransmitting, we should only | |
612 | * send a single packet. | |
f246a7b7 | 613 | * Otherwise, try appending this chunk again. |
1da177e4 | 614 | */ |
8b750ce5 VY |
615 | if (rtx_timeout || fast_rtx) |
616 | done = 1; | |
f246a7b7 VY |
617 | else |
618 | goto redo; | |
1da177e4 | 619 | |
8b750ce5 | 620 | /* Bundle next chunk in the next round. */ |
1da177e4 LT |
621 | break; |
622 | ||
623 | case SCTP_XMIT_RWND_FULL: | |
d808ad9a | 624 | /* Send this packet. */ |
cea8768f | 625 | error = sctp_packet_transmit(pkt, GFP_ATOMIC); |
1da177e4 LT |
626 | |
627 | /* Stop sending DATA as there is no more room | |
628 | * at the receiver. | |
629 | */ | |
8b750ce5 | 630 | done = 1; |
1da177e4 LT |
631 | break; |
632 | ||
526cbef7 | 633 | case SCTP_XMIT_DELAY: |
d808ad9a | 634 | /* Send this packet. */ |
cea8768f | 635 | error = sctp_packet_transmit(pkt, GFP_ATOMIC); |
1da177e4 LT |
636 | |
637 | /* Stop sending DATA because of nagle delay. */ | |
8b750ce5 | 638 | done = 1; |
1da177e4 LT |
639 | break; |
640 | ||
641 | default: | |
642 | /* The append was successful, so add this chunk to | |
643 | * the transmitted list. | |
644 | */ | |
54a27924 WY |
645 | list_move_tail(&chunk->transmitted_list, |
646 | &transport->transmitted); | |
1da177e4 | 647 | |
d808ad9a | 648 | /* Mark the chunk as ineligible for fast retransmit |
1da177e4 LT |
649 | * after it is retransmitted. |
650 | */ | |
c226ef9b NH |
651 | if (chunk->fast_retransmit == SCTP_NEED_FRTX) |
652 | chunk->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 | 653 | |
196d6759 | 654 | q->asoc->stats.rtxchunks++; |
1da177e4 | 655 | break; |
3ff50b79 | 656 | } |
1da177e4 | 657 | |
62aeaff5 VY |
658 | /* Set the timer if there were no errors */ |
659 | if (!error && !timer) | |
660 | timer = 1; | |
661 | ||
8b750ce5 VY |
662 | if (done) |
663 | break; | |
664 | } | |
665 | ||
666 | /* If we are here due to a retransmit timeout or a fast | |
667 | * retransmit and if there are any chunks left in the retransmit | |
668 | * queue that could not fit in the PMTU sized packet, they need | |
669 | * to be marked as ineligible for a subsequent fast retransmit. | |
670 | */ | |
671 | if (rtx_timeout || fast_rtx) { | |
672 | list_for_each_entry(chunk1, lqueue, transmitted_list) { | |
c226ef9b NH |
673 | if (chunk1->fast_retransmit == SCTP_NEED_FRTX) |
674 | chunk1->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 LT |
675 | } |
676 | } | |
677 | ||
62aeaff5 VY |
678 | *start_timer = timer; |
679 | ||
680 | /* Clear fast retransmit hint */ | |
681 | if (fast_rtx) | |
682 | q->fast_rtx = 0; | |
683 | ||
1da177e4 LT |
684 | return error; |
685 | } | |
686 | ||
687 | /* Cork the outqueue so queued chunks are really queued. */ | |
cea8768f | 688 | int sctp_outq_uncork(struct sctp_outq *q, gfp_t gfp) |
1da177e4 | 689 | { |
7d54dc68 | 690 | if (q->cork) |
1da177e4 | 691 | q->cork = 0; |
dacda32e | 692 | |
cea8768f | 693 | return sctp_outq_flush(q, 0, gfp); |
1da177e4 LT |
694 | } |
695 | ||
2e3216cd | 696 | |
1da177e4 LT |
697 | /* |
698 | * Try to flush an outqueue. | |
699 | * | |
700 | * Description: Send everything in q which we legally can, subject to | |
701 | * congestion limitations. | |
702 | * * Note: This function can be called from multiple contexts so appropriate | |
703 | * locking concerns must be made. Today we use the sock lock to protect | |
704 | * this function. | |
705 | */ | |
cea8768f | 706 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp) |
1da177e4 LT |
707 | { |
708 | struct sctp_packet *packet; | |
709 | struct sctp_packet singleton; | |
710 | struct sctp_association *asoc = q->asoc; | |
711 | __u16 sport = asoc->base.bind_addr.port; | |
712 | __u16 dport = asoc->peer.port; | |
713 | __u32 vtag = asoc->peer.i.init_tag; | |
1da177e4 LT |
714 | struct sctp_transport *transport = NULL; |
715 | struct sctp_transport *new_transport; | |
79af02c2 | 716 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
717 | sctp_xmit_t status; |
718 | int error = 0; | |
719 | int start_timer = 0; | |
2e3216cd | 720 | int one_packet = 0; |
1da177e4 LT |
721 | |
722 | /* These transports have chunks to send. */ | |
723 | struct list_head transport_list; | |
724 | struct list_head *ltransport; | |
725 | ||
726 | INIT_LIST_HEAD(&transport_list); | |
727 | packet = NULL; | |
728 | ||
729 | /* | |
730 | * 6.10 Bundling | |
731 | * ... | |
732 | * When bundling control chunks with DATA chunks, an | |
733 | * endpoint MUST place control chunks first in the outbound | |
734 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
735 | * within a SCTP packet in increasing order of TSN. | |
736 | * ... | |
737 | */ | |
738 | ||
79af02c2 | 739 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
8a07eb0a MH |
740 | /* RFC 5061, 5.3 |
741 | * F1) This means that until such time as the ASCONF | |
742 | * containing the add is acknowledged, the sender MUST | |
743 | * NOT use the new IP address as a source for ANY SCTP | |
744 | * packet except on carrying an ASCONF Chunk. | |
745 | */ | |
746 | if (asoc->src_out_of_asoc_ok && | |
747 | chunk->chunk_hdr->type != SCTP_CID_ASCONF) | |
748 | continue; | |
749 | ||
79af02c2 DM |
750 | list_del_init(&chunk->list); |
751 | ||
1da177e4 LT |
752 | /* Pick the right transport to use. */ |
753 | new_transport = chunk->transport; | |
754 | ||
755 | if (!new_transport) { | |
a08de64d VY |
756 | /* |
757 | * If we have a prior transport pointer, see if | |
758 | * the destination address of the chunk | |
759 | * matches the destination address of the | |
760 | * current transport. If not a match, then | |
761 | * try to look up the transport with a given | |
762 | * destination address. We do this because | |
763 | * after processing ASCONFs, we may have new | |
764 | * transports created. | |
765 | */ | |
766 | if (transport && | |
767 | sctp_cmp_addr_exact(&chunk->dest, | |
768 | &transport->ipaddr)) | |
769 | new_transport = transport; | |
770 | else | |
771 | new_transport = sctp_assoc_lookup_paddr(asoc, | |
772 | &chunk->dest); | |
773 | ||
774 | /* if we still don't have a new transport, then | |
775 | * use the current active path. | |
776 | */ | |
777 | if (!new_transport) | |
778 | new_transport = asoc->peer.active_path; | |
ad8fec17 | 779 | } else if ((new_transport->state == SCTP_INACTIVE) || |
5aa93bcf NH |
780 | (new_transport->state == SCTP_UNCONFIRMED) || |
781 | (new_transport->state == SCTP_PF)) { | |
3f7a87d2 FF |
782 | /* If the chunk is Heartbeat or Heartbeat Ack, |
783 | * send it to chunk->transport, even if it's | |
1da177e4 LT |
784 | * inactive. |
785 | * | |
786 | * 3.3.6 Heartbeat Acknowledgement: | |
d808ad9a | 787 | * ... |
1da177e4 LT |
788 | * A HEARTBEAT ACK is always sent to the source IP |
789 | * address of the IP datagram containing the | |
790 | * HEARTBEAT chunk to which this ack is responding. | |
d808ad9a | 791 | * ... |
a08de64d VY |
792 | * |
793 | * ASCONF_ACKs also must be sent to the source. | |
1da177e4 LT |
794 | */ |
795 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && | |
a08de64d VY |
796 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK && |
797 | chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK) | |
1da177e4 LT |
798 | new_transport = asoc->peer.active_path; |
799 | } | |
800 | ||
801 | /* Are we switching transports? | |
802 | * Take care of transport locks. | |
803 | */ | |
804 | if (new_transport != transport) { | |
805 | transport = new_transport; | |
806 | if (list_empty(&transport->send_ready)) { | |
807 | list_add_tail(&transport->send_ready, | |
808 | &transport_list); | |
809 | } | |
810 | packet = &transport->packet; | |
811 | sctp_packet_config(packet, vtag, | |
812 | asoc->peer.ecn_capable); | |
813 | } | |
814 | ||
815 | switch (chunk->chunk_hdr->type) { | |
816 | /* | |
817 | * 6.10 Bundling | |
818 | * ... | |
819 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
820 | * COMPLETE with any other chunks. [Send them immediately.] | |
821 | */ | |
822 | case SCTP_CID_INIT: | |
823 | case SCTP_CID_INIT_ACK: | |
824 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
825 | sctp_packet_init(&singleton, transport, sport, dport); | |
826 | sctp_packet_config(&singleton, vtag, 0); | |
827 | sctp_packet_append_chunk(&singleton, chunk); | |
cea8768f | 828 | error = sctp_packet_transmit(&singleton, gfp); |
1da177e4 LT |
829 | if (error < 0) |
830 | return error; | |
831 | break; | |
832 | ||
833 | case SCTP_CID_ABORT: | |
f4ad85ca GJ |
834 | if (sctp_test_T_bit(chunk)) { |
835 | packet->vtag = asoc->c.my_vtag; | |
836 | } | |
2e3216cd VY |
837 | /* The following chunks are "response" chunks, i.e. |
838 | * they are generated in response to something we | |
839 | * received. If we are sending these, then we can | |
840 | * send only 1 packet containing these chunks. | |
841 | */ | |
1da177e4 | 842 | case SCTP_CID_HEARTBEAT_ACK: |
1da177e4 | 843 | case SCTP_CID_SHUTDOWN_ACK: |
1da177e4 | 844 | case SCTP_CID_COOKIE_ACK: |
2e3216cd VY |
845 | case SCTP_CID_COOKIE_ECHO: |
846 | case SCTP_CID_ERROR: | |
1da177e4 | 847 | case SCTP_CID_ECN_CWR: |
1da177e4 | 848 | case SCTP_CID_ASCONF_ACK: |
2e3216cd | 849 | one_packet = 1; |
25985edc | 850 | /* Fall through */ |
2e3216cd VY |
851 | |
852 | case SCTP_CID_SACK: | |
853 | case SCTP_CID_HEARTBEAT: | |
854 | case SCTP_CID_SHUTDOWN: | |
855 | case SCTP_CID_ECN_ECNE: | |
856 | case SCTP_CID_ASCONF: | |
1da177e4 | 857 | case SCTP_CID_FWD_TSN: |
2e3216cd | 858 | status = sctp_packet_transmit_chunk(packet, chunk, |
cea8768f | 859 | one_packet, gfp); |
2e3216cd VY |
860 | if (status != SCTP_XMIT_OK) { |
861 | /* put the chunk back */ | |
862 | list_add(&chunk->list, &q->control_chunk_list); | |
196d6759 MB |
863 | } else { |
864 | asoc->stats.octrlchunks++; | |
bd69b981 WY |
865 | /* PR-SCTP C5) If a FORWARD TSN is sent, the |
866 | * sender MUST assure that at least one T3-rtx | |
867 | * timer is running. | |
868 | */ | |
196d6759 MB |
869 | if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) |
870 | sctp_transport_reset_timers(transport); | |
2e3216cd | 871 | } |
1da177e4 LT |
872 | break; |
873 | ||
874 | default: | |
875 | /* We built a chunk with an illegal type! */ | |
876 | BUG(); | |
3ff50b79 | 877 | } |
1da177e4 LT |
878 | } |
879 | ||
8a07eb0a MH |
880 | if (q->asoc->src_out_of_asoc_ok) |
881 | goto sctp_flush_out; | |
882 | ||
1da177e4 LT |
883 | /* Is it OK to send data chunks? */ |
884 | switch (asoc->state) { | |
885 | case SCTP_STATE_COOKIE_ECHOED: | |
886 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
887 | * chunk. | |
888 | */ | |
889 | if (!packet || !packet->has_cookie_echo) | |
890 | break; | |
891 | ||
892 | /* fallthru */ | |
893 | case SCTP_STATE_ESTABLISHED: | |
894 | case SCTP_STATE_SHUTDOWN_PENDING: | |
895 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
896 | /* | |
897 | * RFC 2960 6.1 Transmission of DATA Chunks | |
898 | * | |
899 | * C) When the time comes for the sender to transmit, | |
900 | * before sending new DATA chunks, the sender MUST | |
901 | * first transmit any outstanding DATA chunks which | |
902 | * are marked for retransmission (limited by the | |
903 | * current cwnd). | |
904 | */ | |
905 | if (!list_empty(&q->retransmit)) { | |
f207c050 MH |
906 | if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED) |
907 | goto sctp_flush_out; | |
1da177e4 LT |
908 | if (transport == asoc->peer.retran_path) |
909 | goto retran; | |
910 | ||
911 | /* Switch transports & prepare the packet. */ | |
912 | ||
913 | transport = asoc->peer.retran_path; | |
914 | ||
915 | if (list_empty(&transport->send_ready)) { | |
916 | list_add_tail(&transport->send_ready, | |
917 | &transport_list); | |
918 | } | |
919 | ||
920 | packet = &transport->packet; | |
921 | sctp_packet_config(packet, vtag, | |
922 | asoc->peer.ecn_capable); | |
923 | retran: | |
924 | error = sctp_outq_flush_rtx(q, packet, | |
925 | rtx_timeout, &start_timer); | |
926 | ||
927 | if (start_timer) | |
d9efc223 | 928 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
929 | |
930 | /* This can happen on COOKIE-ECHO resend. Only | |
931 | * one chunk can get bundled with a COOKIE-ECHO. | |
932 | */ | |
933 | if (packet->has_cookie_echo) | |
934 | goto sctp_flush_out; | |
935 | ||
936 | /* Don't send new data if there is still data | |
937 | * waiting to retransmit. | |
938 | */ | |
939 | if (!list_empty(&q->retransmit)) | |
940 | goto sctp_flush_out; | |
941 | } | |
942 | ||
46d5a808 VY |
943 | /* Apply Max.Burst limitation to the current transport in |
944 | * case it will be used for new data. We are going to | |
945 | * rest it before we return, but we want to apply the limit | |
946 | * to the currently queued data. | |
947 | */ | |
948 | if (transport) | |
949 | sctp_transport_burst_limited(transport); | |
950 | ||
1da177e4 | 951 | /* Finally, transmit new packets. */ |
1da177e4 LT |
952 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
953 | /* RFC 2960 6.5 Every DATA chunk MUST carry a valid | |
954 | * stream identifier. | |
955 | */ | |
956 | if (chunk->sinfo.sinfo_stream >= | |
957 | asoc->c.sinit_num_ostreams) { | |
958 | ||
959 | /* Mark as failed send. */ | |
960 | sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); | |
961 | sctp_chunk_free(chunk); | |
962 | continue; | |
963 | } | |
964 | ||
965 | /* Has this chunk expired? */ | |
966 | if (sctp_chunk_abandoned(chunk)) { | |
967 | sctp_chunk_fail(chunk, 0); | |
968 | sctp_chunk_free(chunk); | |
969 | continue; | |
970 | } | |
971 | ||
972 | /* If there is a specified transport, use it. | |
973 | * Otherwise, we want to use the active path. | |
974 | */ | |
975 | new_transport = chunk->transport; | |
3f7a87d2 | 976 | if (!new_transport || |
ad8fec17 | 977 | ((new_transport->state == SCTP_INACTIVE) || |
5aa93bcf NH |
978 | (new_transport->state == SCTP_UNCONFIRMED) || |
979 | (new_transport->state == SCTP_PF))) | |
1da177e4 | 980 | new_transport = asoc->peer.active_path; |
f207c050 MH |
981 | if (new_transport->state == SCTP_UNCONFIRMED) |
982 | continue; | |
1da177e4 LT |
983 | |
984 | /* Change packets if necessary. */ | |
985 | if (new_transport != transport) { | |
986 | transport = new_transport; | |
987 | ||
988 | /* Schedule to have this transport's | |
989 | * packet flushed. | |
990 | */ | |
991 | if (list_empty(&transport->send_ready)) { | |
992 | list_add_tail(&transport->send_ready, | |
993 | &transport_list); | |
994 | } | |
995 | ||
996 | packet = &transport->packet; | |
997 | sctp_packet_config(packet, vtag, | |
998 | asoc->peer.ecn_capable); | |
46d5a808 VY |
999 | /* We've switched transports, so apply the |
1000 | * Burst limit to the new transport. | |
1001 | */ | |
1002 | sctp_transport_burst_limited(transport); | |
1da177e4 LT |
1003 | } |
1004 | ||
bb33381d DB |
1005 | pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p " |
1006 | "skb->users:%d\n", | |
1007 | __func__, q, chunk, chunk && chunk->chunk_hdr ? | |
1008 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
1009 | "illegal chunk", ntohl(chunk->subh.data_hdr->tsn), | |
1010 | chunk->skb ? chunk->skb->head : NULL, chunk->skb ? | |
1011 | atomic_read(&chunk->skb->users) : -1); | |
1da177e4 LT |
1012 | |
1013 | /* Add the chunk to the packet. */ | |
cea8768f | 1014 | status = sctp_packet_transmit_chunk(packet, chunk, 0, gfp); |
1da177e4 LT |
1015 | |
1016 | switch (status) { | |
1017 | case SCTP_XMIT_PMTU_FULL: | |
1018 | case SCTP_XMIT_RWND_FULL: | |
526cbef7 | 1019 | case SCTP_XMIT_DELAY: |
1da177e4 LT |
1020 | /* We could not append this chunk, so put |
1021 | * the chunk back on the output queue. | |
1022 | */ | |
bb33381d DB |
1023 | pr_debug("%s: could not transmit tsn:0x%x, status:%d\n", |
1024 | __func__, ntohl(chunk->subh.data_hdr->tsn), | |
1025 | status); | |
1026 | ||
1da177e4 LT |
1027 | sctp_outq_head_data(q, chunk); |
1028 | goto sctp_flush_out; | |
1da177e4 LT |
1029 | |
1030 | case SCTP_XMIT_OK: | |
b93d6471 WY |
1031 | /* The sender is in the SHUTDOWN-PENDING state, |
1032 | * The sender MAY set the I-bit in the DATA | |
1033 | * chunk header. | |
1034 | */ | |
1035 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) | |
1036 | chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; | |
196d6759 MB |
1037 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) |
1038 | asoc->stats.ouodchunks++; | |
1039 | else | |
1040 | asoc->stats.oodchunks++; | |
b93d6471 | 1041 | |
1da177e4 LT |
1042 | break; |
1043 | ||
1044 | default: | |
1045 | BUG(); | |
1046 | } | |
1047 | ||
d808ad9a | 1048 | /* BUG: We assume that the sctp_packet_transmit() |
1da177e4 LT |
1049 | * call below will succeed all the time and add the |
1050 | * chunk to the transmitted list and restart the | |
1051 | * timers. | |
1052 | * It is possible that the call can fail under OOM | |
1053 | * conditions. | |
1054 | * | |
1055 | * Is this really a problem? Won't this behave | |
1056 | * like a lost TSN? | |
1057 | */ | |
1058 | list_add_tail(&chunk->transmitted_list, | |
1059 | &transport->transmitted); | |
1060 | ||
d9efc223 | 1061 | sctp_transport_reset_timers(transport); |
1da177e4 | 1062 | |
1da177e4 LT |
1063 | /* Only let one DATA chunk get bundled with a |
1064 | * COOKIE-ECHO chunk. | |
1065 | */ | |
1066 | if (packet->has_cookie_echo) | |
1067 | goto sctp_flush_out; | |
1068 | } | |
1069 | break; | |
1070 | ||
1071 | default: | |
1072 | /* Do nothing. */ | |
1073 | break; | |
1074 | } | |
1075 | ||
1076 | sctp_flush_out: | |
1077 | ||
1078 | /* Before returning, examine all the transports touched in | |
1079 | * this call. Right now, we bluntly force clear all the | |
1080 | * transports. Things might change after we implement Nagle. | |
1081 | * But such an examination is still required. | |
1082 | * | |
1083 | * --xguo | |
1084 | */ | |
cb3f837b | 1085 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL) { |
1da177e4 LT |
1086 | struct sctp_transport *t = list_entry(ltransport, |
1087 | struct sctp_transport, | |
1088 | send_ready); | |
1089 | packet = &t->packet; | |
1090 | if (!sctp_packet_empty(packet)) | |
cea8768f | 1091 | error = sctp_packet_transmit(packet, gfp); |
46d5a808 VY |
1092 | |
1093 | /* Clear the burst limited state, if any */ | |
1094 | sctp_transport_burst_reset(t); | |
1da177e4 LT |
1095 | } |
1096 | ||
1097 | return error; | |
1098 | } | |
1099 | ||
1100 | /* Update unack_data based on the incoming SACK chunk */ | |
1101 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
1102 | struct sctp_sackhdr *sack) | |
1103 | { | |
1104 | sctp_sack_variable_t *frags; | |
1105 | __u16 unack_data; | |
1106 | int i; | |
1107 | ||
1108 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
1109 | ||
1110 | frags = sack->variable; | |
1111 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
1112 | unack_data -= ((ntohs(frags[i].gab.end) - | |
1113 | ntohs(frags[i].gab.start) + 1)); | |
1114 | } | |
1115 | ||
1116 | assoc->unack_data = unack_data; | |
1117 | } | |
1118 | ||
1da177e4 LT |
1119 | /* This is where we REALLY process a SACK. |
1120 | * | |
1121 | * Process the SACK against the outqueue. Mostly, this just frees | |
1122 | * things off the transmitted queue. | |
1123 | */ | |
edfee033 | 1124 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk) |
1da177e4 LT |
1125 | { |
1126 | struct sctp_association *asoc = q->asoc; | |
edfee033 | 1127 | struct sctp_sackhdr *sack = chunk->subh.sack_hdr; |
1da177e4 LT |
1128 | struct sctp_transport *transport; |
1129 | struct sctp_chunk *tchunk = NULL; | |
9dbc15f0 | 1130 | struct list_head *lchunk, *transport_list, *temp; |
1da177e4 LT |
1131 | sctp_sack_variable_t *frags = sack->variable; |
1132 | __u32 sack_ctsn, ctsn, tsn; | |
1133 | __u32 highest_tsn, highest_new_tsn; | |
1134 | __u32 sack_a_rwnd; | |
95c96174 | 1135 | unsigned int outstanding; |
1da177e4 LT |
1136 | struct sctp_transport *primary = asoc->peer.primary_path; |
1137 | int count_of_newacks = 0; | |
2cd9b822 | 1138 | int gap_ack_blocks; |
ea862c8d | 1139 | u8 accum_moved = 0; |
1da177e4 LT |
1140 | |
1141 | /* Grab the association's destination address list. */ | |
1142 | transport_list = &asoc->peer.transport_addr_list; | |
1143 | ||
1144 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
2cd9b822 | 1145 | gap_ack_blocks = ntohs(sack->num_gap_ack_blocks); |
196d6759 | 1146 | asoc->stats.gapcnt += gap_ack_blocks; |
1da177e4 LT |
1147 | /* |
1148 | * SFR-CACC algorithm: | |
1149 | * On receipt of a SACK the sender SHOULD execute the | |
1150 | * following statements. | |
1151 | * | |
1152 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1153 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1154 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1155 | * all destinations. | |
1da177e4 LT |
1156 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
1157 | * is set the receiver of the SACK MUST take the following actions: | |
1158 | * | |
1159 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1160 | * addresses. | |
ab5216a5 VY |
1161 | * |
1162 | * Only bother if changeover_active is set. Otherwise, this is | |
1163 | * totally suboptimal to do on every SACK. | |
1da177e4 | 1164 | */ |
ab5216a5 VY |
1165 | if (primary->cacc.changeover_active) { |
1166 | u8 clear_cycling = 0; | |
1167 | ||
1168 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1169 | primary->cacc.changeover_active = 0; | |
1170 | clear_cycling = 1; | |
1171 | } | |
1172 | ||
1173 | if (clear_cycling || gap_ack_blocks) { | |
1174 | list_for_each_entry(transport, transport_list, | |
1175 | transports) { | |
1176 | if (clear_cycling) | |
1177 | transport->cacc.cycling_changeover = 0; | |
1178 | if (gap_ack_blocks) | |
1179 | transport->cacc.cacc_saw_newack = 0; | |
1180 | } | |
1da177e4 LT |
1181 | } |
1182 | } | |
1183 | ||
1184 | /* Get the highest TSN in the sack. */ | |
1185 | highest_tsn = sack_ctsn; | |
2cd9b822 VY |
1186 | if (gap_ack_blocks) |
1187 | highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); | |
1da177e4 | 1188 | |
bfa0d984 | 1189 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) |
1da177e4 | 1190 | asoc->highest_sacked = highest_tsn; |
1da177e4 | 1191 | |
bfa0d984 | 1192 | highest_new_tsn = sack_ctsn; |
2cd9b822 | 1193 | |
1da177e4 LT |
1194 | /* Run through the retransmit queue. Credit bytes received |
1195 | * and free those chunks that we can. | |
1196 | */ | |
edfee033 | 1197 | sctp_check_transmitted(q, &q->retransmit, NULL, NULL, sack, &highest_new_tsn); |
1da177e4 LT |
1198 | |
1199 | /* Run through the transmitted queue. | |
1200 | * Credit bytes received and free those chunks which we can. | |
1201 | * | |
1202 | * This is a MASSIVE candidate for optimization. | |
1203 | */ | |
9dbc15f0 | 1204 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 | 1205 | sctp_check_transmitted(q, &transport->transmitted, |
edfee033 ND |
1206 | transport, &chunk->source, sack, |
1207 | &highest_new_tsn); | |
1da177e4 LT |
1208 | /* |
1209 | * SFR-CACC algorithm: | |
1210 | * C) Let count_of_newacks be the number of | |
1211 | * destinations for which cacc_saw_newack is set. | |
1212 | */ | |
1213 | if (transport->cacc.cacc_saw_newack) | |
cb3f837b | 1214 | count_of_newacks++; |
1da177e4 LT |
1215 | } |
1216 | ||
ea862c8d VY |
1217 | /* Move the Cumulative TSN Ack Point if appropriate. */ |
1218 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) { | |
1219 | asoc->ctsn_ack_point = sack_ctsn; | |
1220 | accum_moved = 1; | |
1221 | } | |
1222 | ||
2cd9b822 | 1223 | if (gap_ack_blocks) { |
ea862c8d VY |
1224 | |
1225 | if (asoc->fast_recovery && accum_moved) | |
1226 | highest_new_tsn = highest_tsn; | |
1227 | ||
2cd9b822 VY |
1228 | list_for_each_entry(transport, transport_list, transports) |
1229 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1230 | highest_new_tsn, count_of_newacks); | |
1da177e4 LT |
1231 | } |
1232 | ||
1da177e4 LT |
1233 | /* Update unack_data field in the assoc. */ |
1234 | sctp_sack_update_unack_data(asoc, sack); | |
1235 | ||
1236 | ctsn = asoc->ctsn_ack_point; | |
1237 | ||
1238 | /* Throw away stuff rotting on the sack queue. */ | |
1239 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1240 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1241 | transmitted_list); | |
1242 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
5f9646c3 VY |
1243 | if (TSN_lte(tsn, ctsn)) { |
1244 | list_del_init(&tchunk->transmitted_list); | |
1da177e4 | 1245 | sctp_chunk_free(tchunk); |
5f9646c3 | 1246 | } |
1da177e4 LT |
1247 | } |
1248 | ||
1249 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1250 | * number of bytes still outstanding after processing the | |
1251 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1252 | */ | |
1253 | ||
1254 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
8a0d19c5 | 1255 | asoc->peer.zero_window_announced = !sack_a_rwnd; |
1da177e4 LT |
1256 | outstanding = q->outstanding_bytes; |
1257 | ||
1258 | if (outstanding < sack_a_rwnd) | |
1259 | sack_a_rwnd -= outstanding; | |
1260 | else | |
1261 | sack_a_rwnd = 0; | |
1262 | ||
1263 | asoc->peer.rwnd = sack_a_rwnd; | |
1264 | ||
1265 | sctp_generate_fwdtsn(q, sack_ctsn); | |
1266 | ||
bb33381d DB |
1267 | pr_debug("%s: sack cumulative tsn ack:0x%x\n", __func__, sack_ctsn); |
1268 | pr_debug("%s: cumulative tsn ack of assoc:%p is 0x%x, " | |
1269 | "advertised peer ack point:0x%x\n", __func__, asoc, ctsn, | |
1270 | asoc->adv_peer_ack_point); | |
1da177e4 | 1271 | |
619a60ee | 1272 | return sctp_outq_is_empty(q); |
1da177e4 LT |
1273 | } |
1274 | ||
619a60ee VY |
1275 | /* Is the outqueue empty? |
1276 | * The queue is empty when we have not pending data, no in-flight data | |
1277 | * and nothing pending retransmissions. | |
1278 | */ | |
1da177e4 LT |
1279 | int sctp_outq_is_empty(const struct sctp_outq *q) |
1280 | { | |
619a60ee VY |
1281 | return q->out_qlen == 0 && q->outstanding_bytes == 0 && |
1282 | list_empty(&q->retransmit); | |
1da177e4 LT |
1283 | } |
1284 | ||
1285 | /******************************************************************** | |
1286 | * 2nd Level Abstractions | |
1287 | ********************************************************************/ | |
1288 | ||
1289 | /* Go through a transport's transmitted list or the association's retransmit | |
1290 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1291 | * The retransmit list will not have an associated transport. | |
1292 | * | |
1293 | * I added coherent debug information output. --xguo | |
1294 | * | |
1295 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1296 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1297 | * KEPT TSN6-TSN7, etc. | |
1298 | */ | |
1299 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1300 | struct list_head *transmitted_queue, | |
1301 | struct sctp_transport *transport, | |
edfee033 | 1302 | union sctp_addr *saddr, |
1da177e4 | 1303 | struct sctp_sackhdr *sack, |
bfa0d984 | 1304 | __u32 *highest_new_tsn_in_sack) |
1da177e4 LT |
1305 | { |
1306 | struct list_head *lchunk; | |
1307 | struct sctp_chunk *tchunk; | |
1308 | struct list_head tlist; | |
1309 | __u32 tsn; | |
1310 | __u32 sack_ctsn; | |
1311 | __u32 rtt; | |
1312 | __u8 restart_timer = 0; | |
1313 | int bytes_acked = 0; | |
31b02e15 | 1314 | int migrate_bytes = 0; |
8c2f414a | 1315 | bool forward_progress = false; |
1da177e4 | 1316 | |
1da177e4 LT |
1317 | sack_ctsn = ntohl(sack->cum_tsn_ack); |
1318 | ||
1319 | INIT_LIST_HEAD(&tlist); | |
1320 | ||
1321 | /* The while loop will skip empty transmitted queues. */ | |
1322 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1323 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1324 | transmitted_list); | |
1325 | ||
1326 | if (sctp_chunk_abandoned(tchunk)) { | |
1327 | /* Move the chunk to abandoned list. */ | |
1328 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
1329 | |
1330 | /* If this chunk has not been acked, stop | |
1331 | * considering it as 'outstanding'. | |
1332 | */ | |
1333 | if (!tchunk->tsn_gap_acked) { | |
31b02e15 VY |
1334 | if (tchunk->transport) |
1335 | tchunk->transport->flight_size -= | |
1336 | sctp_data_size(tchunk); | |
8c4a2d41 VY |
1337 | q->outstanding_bytes -= sctp_data_size(tchunk); |
1338 | } | |
1da177e4 LT |
1339 | continue; |
1340 | } | |
1341 | ||
1342 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1343 | if (sctp_acked(sack, tsn)) { | |
1344 | /* If this queue is the retransmit queue, the | |
1345 | * retransmit timer has already reclaimed | |
1346 | * the outstanding bytes for this chunk, so only | |
1347 | * count bytes associated with a transport. | |
1348 | */ | |
1349 | if (transport) { | |
1350 | /* If this chunk is being used for RTT | |
1351 | * measurement, calculate the RTT and update | |
1352 | * the RTO using this value. | |
1353 | * | |
1354 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1355 | * MUST NOT be made using packets that were | |
1356 | * retransmitted (and thus for which it is | |
1357 | * ambiguous whether the reply was for the | |
1358 | * first instance of the packet or a later | |
1359 | * instance). | |
1360 | */ | |
d808ad9a | 1361 | if (!tchunk->tsn_gap_acked && |
6eabca54 | 1362 | !tchunk->resent && |
1da177e4 | 1363 | tchunk->rtt_in_progress) { |
4c9f5d53 | 1364 | tchunk->rtt_in_progress = 0; |
1da177e4 LT |
1365 | rtt = jiffies - tchunk->sent_at; |
1366 | sctp_transport_update_rto(transport, | |
1367 | rtt); | |
1368 | } | |
1369 | } | |
31b02e15 VY |
1370 | |
1371 | /* If the chunk hasn't been marked as ACKED, | |
1372 | * mark it and account bytes_acked if the | |
1373 | * chunk had a valid transport (it will not | |
1374 | * have a transport if ASCONF had deleted it | |
1375 | * while DATA was outstanding). | |
1376 | */ | |
1377 | if (!tchunk->tsn_gap_acked) { | |
1378 | tchunk->tsn_gap_acked = 1; | |
d6c41614 CX |
1379 | if (TSN_lt(*highest_new_tsn_in_sack, tsn)) |
1380 | *highest_new_tsn_in_sack = tsn; | |
31b02e15 VY |
1381 | bytes_acked += sctp_data_size(tchunk); |
1382 | if (!tchunk->transport) | |
1383 | migrate_bytes += sctp_data_size(tchunk); | |
8c2f414a | 1384 | forward_progress = true; |
31b02e15 VY |
1385 | } |
1386 | ||
d808ad9a | 1387 | if (TSN_lte(tsn, sack_ctsn)) { |
1da177e4 LT |
1388 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
1389 | * | |
1390 | * R3) Whenever a SACK is received | |
1391 | * that acknowledges the DATA chunk | |
1392 | * with the earliest outstanding TSN | |
1393 | * for that address, restart T3-rtx | |
1394 | * timer for that address with its | |
1395 | * current RTO. | |
1396 | */ | |
1397 | restart_timer = 1; | |
8c2f414a | 1398 | forward_progress = true; |
1da177e4 LT |
1399 | |
1400 | if (!tchunk->tsn_gap_acked) { | |
1da177e4 LT |
1401 | /* |
1402 | * SFR-CACC algorithm: | |
1403 | * 2) If the SACK contains gap acks | |
1404 | * and the flag CHANGEOVER_ACTIVE is | |
1405 | * set the receiver of the SACK MUST | |
1406 | * take the following action: | |
1407 | * | |
1408 | * B) For each TSN t being acked that | |
1409 | * has not been acked in any SACK so | |
1410 | * far, set cacc_saw_newack to 1 for | |
1411 | * the destination that the TSN was | |
1412 | * sent to. | |
1413 | */ | |
1414 | if (transport && | |
1415 | sack->num_gap_ack_blocks && | |
1416 | q->asoc->peer.primary_path->cacc. | |
1417 | changeover_active) | |
1418 | transport->cacc.cacc_saw_newack | |
1419 | = 1; | |
1420 | } | |
1421 | ||
1422 | list_add_tail(&tchunk->transmitted_list, | |
1423 | &q->sacked); | |
1424 | } else { | |
1425 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1426 | * M2) Each time a SACK arrives reporting | |
1427 | * 'Stray DATA chunk(s)' record the highest TSN | |
1428 | * reported as newly acknowledged, call this | |
1429 | * value 'HighestTSNinSack'. A newly | |
1430 | * acknowledged DATA chunk is one not | |
1431 | * previously acknowledged in a SACK. | |
1432 | * | |
1433 | * When the SCTP sender of data receives a SACK | |
1434 | * chunk that acknowledges, for the first time, | |
1435 | * the receipt of a DATA chunk, all the still | |
1436 | * unacknowledged DATA chunks whose TSN is | |
1437 | * older than that newly acknowledged DATA | |
1438 | * chunk, are qualified as 'Stray DATA chunks'. | |
1439 | */ | |
1da177e4 LT |
1440 | list_add_tail(lchunk, &tlist); |
1441 | } | |
1da177e4 LT |
1442 | } else { |
1443 | if (tchunk->tsn_gap_acked) { | |
bb33381d DB |
1444 | pr_debug("%s: receiver reneged on data TSN:0x%x\n", |
1445 | __func__, tsn); | |
1446 | ||
1da177e4 LT |
1447 | tchunk->tsn_gap_acked = 0; |
1448 | ||
31b02e15 VY |
1449 | if (tchunk->transport) |
1450 | bytes_acked -= sctp_data_size(tchunk); | |
1da177e4 LT |
1451 | |
1452 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1453 | * | |
1454 | * R4) Whenever a SACK is received missing a | |
1455 | * TSN that was previously acknowledged via a | |
1456 | * Gap Ack Block, start T3-rtx for the | |
1457 | * destination address to which the DATA | |
1458 | * chunk was originally | |
1459 | * transmitted if it is not already running. | |
1460 | */ | |
1461 | restart_timer = 1; | |
1462 | } | |
1463 | ||
1464 | list_add_tail(lchunk, &tlist); | |
1da177e4 LT |
1465 | } |
1466 | } | |
1467 | ||
1da177e4 LT |
1468 | if (transport) { |
1469 | if (bytes_acked) { | |
f8d96052 TG |
1470 | struct sctp_association *asoc = transport->asoc; |
1471 | ||
31b02e15 VY |
1472 | /* We may have counted DATA that was migrated |
1473 | * to this transport due to DEL-IP operation. | |
1474 | * Subtract those bytes, since the were never | |
1475 | * send on this transport and shouldn't be | |
1476 | * credited to this transport. | |
1477 | */ | |
1478 | bytes_acked -= migrate_bytes; | |
1479 | ||
1da177e4 LT |
1480 | /* 8.2. When an outstanding TSN is acknowledged, |
1481 | * the endpoint shall clear the error counter of | |
1482 | * the destination transport address to which the | |
1483 | * DATA chunk was last sent. | |
1484 | * The association's overall error counter is | |
1485 | * also cleared. | |
1486 | */ | |
1487 | transport->error_count = 0; | |
1488 | transport->asoc->overall_error_count = 0; | |
8c2f414a | 1489 | forward_progress = true; |
1da177e4 | 1490 | |
f8d96052 TG |
1491 | /* |
1492 | * While in SHUTDOWN PENDING, we may have started | |
1493 | * the T5 shutdown guard timer after reaching the | |
1494 | * retransmission limit. Stop that timer as soon | |
1495 | * as the receiver acknowledged any data. | |
1496 | */ | |
1497 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING && | |
1498 | del_timer(&asoc->timers | |
1499 | [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD])) | |
1500 | sctp_association_put(asoc); | |
1501 | ||
1da177e4 LT |
1502 | /* Mark the destination transport address as |
1503 | * active if it is not so marked. | |
1504 | */ | |
edfee033 ND |
1505 | if ((transport->state == SCTP_INACTIVE || |
1506 | transport->state == SCTP_UNCONFIRMED) && | |
1507 | sctp_cmp_addr_exact(&transport->ipaddr, saddr)) { | |
1da177e4 LT |
1508 | sctp_assoc_control_transport( |
1509 | transport->asoc, | |
1510 | transport, | |
1511 | SCTP_TRANSPORT_UP, | |
1512 | SCTP_RECEIVED_SACK); | |
1513 | } | |
1514 | ||
1515 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1516 | bytes_acked); | |
1517 | ||
1518 | transport->flight_size -= bytes_acked; | |
8b73a07c GJ |
1519 | if (transport->flight_size == 0) |
1520 | transport->partial_bytes_acked = 0; | |
31b02e15 | 1521 | q->outstanding_bytes -= bytes_acked + migrate_bytes; |
1da177e4 LT |
1522 | } else { |
1523 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1524 | * When a sender is doing zero window probing, it | |
1525 | * should not timeout the association if it continues | |
1526 | * to receive new packets from the receiver. The | |
1527 | * reason is that the receiver MAY keep its window | |
1528 | * closed for an indefinite time. | |
1529 | * A sender is doing zero window probing when the | |
1530 | * receiver's advertised window is zero, and there is | |
1531 | * only one data chunk in flight to the receiver. | |
f8d96052 TG |
1532 | * |
1533 | * Allow the association to timeout while in SHUTDOWN | |
1534 | * PENDING or SHUTDOWN RECEIVED in case the receiver | |
1535 | * stays in zero window mode forever. | |
1da177e4 LT |
1536 | */ |
1537 | if (!q->asoc->peer.rwnd && | |
1538 | !list_empty(&tlist) && | |
f8d96052 TG |
1539 | (sack_ctsn+2 == q->asoc->next_tsn) && |
1540 | q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) { | |
bb33381d DB |
1541 | pr_debug("%s: sack received for zero window " |
1542 | "probe:%u\n", __func__, sack_ctsn); | |
1543 | ||
1da177e4 LT |
1544 | q->asoc->overall_error_count = 0; |
1545 | transport->error_count = 0; | |
1546 | } | |
1547 | } | |
1548 | ||
1549 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1550 | * | |
1551 | * R2) Whenever all outstanding data sent to an address have | |
1552 | * been acknowledged, turn off the T3-rtx timer of that | |
1553 | * address. | |
1554 | */ | |
1555 | if (!transport->flight_size) { | |
25cc4ae9 | 1556 | if (del_timer(&transport->T3_rtx_timer)) |
1da177e4 | 1557 | sctp_transport_put(transport); |
1da177e4 LT |
1558 | } else if (restart_timer) { |
1559 | if (!mod_timer(&transport->T3_rtx_timer, | |
1560 | jiffies + transport->rto)) | |
1561 | sctp_transport_hold(transport); | |
1562 | } | |
8c2f414a DB |
1563 | |
1564 | if (forward_progress) { | |
1565 | if (transport->dst) | |
1566 | dst_confirm(transport->dst); | |
1567 | } | |
1da177e4 LT |
1568 | } |
1569 | ||
1570 | list_splice(&tlist, transmitted_queue); | |
1571 | } | |
1572 | ||
1573 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1574 | static void sctp_mark_missing(struct sctp_outq *q, | |
1575 | struct list_head *transmitted_queue, | |
1576 | struct sctp_transport *transport, | |
1577 | __u32 highest_new_tsn_in_sack, | |
1578 | int count_of_newacks) | |
1579 | { | |
1580 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1581 | __u32 tsn; |
1582 | char do_fast_retransmit = 0; | |
ea862c8d VY |
1583 | struct sctp_association *asoc = q->asoc; |
1584 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1da177e4 | 1585 | |
9dbc15f0 | 1586 | list_for_each_entry(chunk, transmitted_queue, transmitted_list) { |
1da177e4 | 1587 | |
1da177e4 LT |
1588 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1589 | ||
1590 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1591 | * 'Unacknowledged TSN's', if the TSN number of an | |
1592 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1593 | * value, increment the 'TSN.Missing.Report' count on that | |
1594 | * chunk if it has NOT been fast retransmitted or marked for | |
1595 | * fast retransmit already. | |
1596 | */ | |
c226ef9b | 1597 | if (chunk->fast_retransmit == SCTP_CAN_FRTX && |
1da177e4 LT |
1598 | !chunk->tsn_gap_acked && |
1599 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1600 | ||
1601 | /* SFR-CACC may require us to skip marking | |
1602 | * this chunk as missing. | |
1603 | */ | |
f246a7b7 VY |
1604 | if (!transport || !sctp_cacc_skip(primary, |
1605 | chunk->transport, | |
1606 | count_of_newacks, tsn)) { | |
1da177e4 LT |
1607 | chunk->tsn_missing_report++; |
1608 | ||
bb33381d DB |
1609 | pr_debug("%s: tsn:0x%x missing counter:%d\n", |
1610 | __func__, tsn, chunk->tsn_missing_report); | |
1da177e4 LT |
1611 | } |
1612 | } | |
1613 | /* | |
1614 | * M4) If any DATA chunk is found to have a | |
1615 | * 'TSN.Missing.Report' | |
27852c26 | 1616 | * value larger than or equal to 3, mark that chunk for |
1da177e4 LT |
1617 | * retransmission and start the fast retransmit procedure. |
1618 | */ | |
1619 | ||
27852c26 | 1620 | if (chunk->tsn_missing_report >= 3) { |
c226ef9b | 1621 | chunk->fast_retransmit = SCTP_NEED_FRTX; |
1da177e4 LT |
1622 | do_fast_retransmit = 1; |
1623 | } | |
1624 | } | |
1625 | ||
1626 | if (transport) { | |
1627 | if (do_fast_retransmit) | |
1628 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1629 | ||
bb33381d DB |
1630 | pr_debug("%s: transport:%p, cwnd:%d, ssthresh:%d, " |
1631 | "flight_size:%d, pba:%d\n", __func__, transport, | |
1632 | transport->cwnd, transport->ssthresh, | |
1633 | transport->flight_size, transport->partial_bytes_acked); | |
1da177e4 LT |
1634 | } |
1635 | } | |
1636 | ||
1637 | /* Is the given TSN acked by this packet? */ | |
1638 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1639 | { | |
1640 | int i; | |
1641 | sctp_sack_variable_t *frags; | |
1642 | __u16 gap; | |
1643 | __u32 ctsn = ntohl(sack->cum_tsn_ack); | |
1644 | ||
d808ad9a | 1645 | if (TSN_lte(tsn, ctsn)) |
1da177e4 LT |
1646 | goto pass; |
1647 | ||
1648 | /* 3.3.4 Selective Acknowledgement (SACK) (3): | |
1649 | * | |
1650 | * Gap Ack Blocks: | |
1651 | * These fields contain the Gap Ack Blocks. They are repeated | |
1652 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1653 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1654 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1655 | * Ack + Gap Ack Block Start) and less than or equal to | |
1656 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1657 | * Block are assumed to have been received correctly. | |
1658 | */ | |
1659 | ||
1660 | frags = sack->variable; | |
1661 | gap = tsn - ctsn; | |
1662 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { | |
1663 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && | |
1664 | TSN_lte(gap, ntohs(frags[i].gab.end))) | |
1665 | goto pass; | |
1666 | } | |
1667 | ||
1668 | return 0; | |
1669 | pass: | |
1670 | return 1; | |
1671 | } | |
1672 | ||
1673 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
9f81bcd9 | 1674 | int nskips, __be16 stream) |
1da177e4 LT |
1675 | { |
1676 | int i; | |
1677 | ||
1678 | for (i = 0; i < nskips; i++) { | |
1679 | if (skiplist[i].stream == stream) | |
1680 | return i; | |
1681 | } | |
1682 | return i; | |
1683 | } | |
1684 | ||
1685 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
1686 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) | |
1687 | { | |
1688 | struct sctp_association *asoc = q->asoc; | |
1689 | struct sctp_chunk *ftsn_chunk = NULL; | |
1690 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1691 | int nskips = 0; | |
1692 | int skip_pos = 0; | |
1693 | __u32 tsn; | |
1694 | struct sctp_chunk *chunk; | |
1695 | struct list_head *lchunk, *temp; | |
1696 | ||
76595024 WY |
1697 | if (!asoc->peer.prsctp_capable) |
1698 | return; | |
1699 | ||
1da177e4 LT |
1700 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
1701 | * received SACK. | |
d808ad9a | 1702 | * |
1da177e4 LT |
1703 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
1704 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1705 | */ | |
1706 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1707 | asoc->adv_peer_ack_point = ctsn; | |
1708 | ||
1709 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1710 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1711 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1712 | * shown in the following example: | |
1713 | * | |
1714 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1715 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
d808ad9a | 1716 | * |
1da177e4 LT |
1717 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
1718 | * normal SACK processing local advancement | |
1719 | * ... ... | |
1720 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1721 | * 103 abandoned 103 abandoned | |
1722 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1723 | * 105 105 | |
1724 | * 106 acked 106 acked | |
1725 | * ... ... | |
1726 | * | |
1727 | * In this example, the data sender successfully advanced the | |
1728 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1729 | */ | |
1730 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1731 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1732 | transmitted_list); | |
1733 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1734 | ||
1735 | /* Remove any chunks in the abandoned queue that are acked by | |
1736 | * the ctsn. | |
d808ad9a | 1737 | */ |
1da177e4 LT |
1738 | if (TSN_lte(tsn, ctsn)) { |
1739 | list_del_init(lchunk); | |
1da177e4 LT |
1740 | sctp_chunk_free(chunk); |
1741 | } else { | |
1742 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1743 | asoc->adv_peer_ack_point = tsn; | |
1744 | if (chunk->chunk_hdr->flags & | |
1745 | SCTP_DATA_UNORDERED) | |
1746 | continue; | |
1747 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1748 | nskips, | |
1749 | chunk->subh.data_hdr->stream); | |
1750 | ftsn_skip_arr[skip_pos].stream = | |
1751 | chunk->subh.data_hdr->stream; | |
1752 | ftsn_skip_arr[skip_pos].ssn = | |
1753 | chunk->subh.data_hdr->ssn; | |
1754 | if (skip_pos == nskips) | |
1755 | nskips++; | |
1756 | if (nskips == 10) | |
1757 | break; | |
1758 | } else | |
1759 | break; | |
1760 | } | |
1761 | } | |
1762 | ||
1763 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1764 | * is greater than the Cumulative TSN ACK carried in the received | |
1765 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1766 | * chunk containing the latest value of the | |
1767 | * "Advanced.Peer.Ack.Point". | |
1768 | * | |
1769 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1770 | * list each stream and sequence number in the forwarded TSN. This | |
1771 | * information will enable the receiver to easily find any | |
1772 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1773 | * SHOULD only be reported once; this means that if multiple | |
1774 | * abandoned messages occur in the same stream then only the | |
1775 | * highest abandoned stream sequence number is reported. If the | |
1776 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1777 | * the sender of the FORWARD TSN SHOULD lower the | |
1778 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1779 | * single MTU. | |
1780 | */ | |
1781 | if (asoc->adv_peer_ack_point > ctsn) | |
1782 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
d808ad9a | 1783 | nskips, &ftsn_skip_arr[0]); |
1da177e4 LT |
1784 | |
1785 | if (ftsn_chunk) { | |
79af02c2 | 1786 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
b01a2407 | 1787 | SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
1788 | } |
1789 | } |