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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 | |
25 | * along with GNU CC; see the file COPYING. If not, write to | |
26 | * the Free Software Foundation, 59 Temple Place - Suite 330, | |
27 | * Boston, MA 02111-1307, USA. | |
28 | * | |
29 | * Please send any bug reports or fixes you make to the | |
30 | * email address(es): | |
31 | * lksctp developers <lksctp-developers@lists.sourceforge.net> | |
32 | * | |
33 | * Or submit a bug report through the following website: | |
34 | * http://www.sf.net/projects/lksctp | |
35 | * | |
36 | * Written or modified by: | |
37 | * La Monte H.P. Yarroll <piggy@acm.org> | |
38 | * Karl Knutson <karl@athena.chicago.il.us> | |
39 | * Perry Melange <pmelange@null.cc.uic.edu> | |
40 | * Xingang Guo <xingang.guo@intel.com> | |
41 | * Hui Huang <hui.huang@nokia.com> | |
42 | * Sridhar Samudrala <sri@us.ibm.com> | |
43 | * Jon Grimm <jgrimm@us.ibm.com> | |
44 | * | |
45 | * Any bugs reported given to us we will try to fix... any fixes shared will | |
46 | * be incorporated into the next SCTP release. | |
47 | */ | |
48 | ||
49 | #include <linux/types.h> | |
50 | #include <linux/list.h> /* For struct list_head */ | |
51 | #include <linux/socket.h> | |
52 | #include <linux/ip.h> | |
5a0e3ad6 | 53 | #include <linux/slab.h> |
1da177e4 LT |
54 | #include <net/sock.h> /* For skb_set_owner_w */ |
55 | ||
56 | #include <net/sctp/sctp.h> | |
57 | #include <net/sctp/sm.h> | |
58 | ||
59 | /* Declare internal functions here. */ | |
60 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); | |
61 | static void sctp_check_transmitted(struct sctp_outq *q, | |
62 | struct list_head *transmitted_queue, | |
63 | struct sctp_transport *transport, | |
64 | struct sctp_sackhdr *sack, | |
65 | __u32 highest_new_tsn); | |
66 | ||
67 | static void sctp_mark_missing(struct sctp_outq *q, | |
68 | struct list_head *transmitted_queue, | |
69 | struct sctp_transport *transport, | |
70 | __u32 highest_new_tsn, | |
71 | int count_of_newacks); | |
72 | ||
73 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); | |
74 | ||
abd0b198 AB |
75 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout); |
76 | ||
1da177e4 LT |
77 | /* Add data to the front of the queue. */ |
78 | static inline void sctp_outq_head_data(struct sctp_outq *q, | |
79 | struct sctp_chunk *ch) | |
80 | { | |
79af02c2 | 81 | list_add(&ch->list, &q->out_chunk_list); |
1da177e4 LT |
82 | q->out_qlen += ch->skb->len; |
83 | return; | |
84 | } | |
85 | ||
86 | /* Take data from the front of the queue. */ | |
87 | static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) | |
88 | { | |
79af02c2 DM |
89 | struct sctp_chunk *ch = NULL; |
90 | ||
91 | if (!list_empty(&q->out_chunk_list)) { | |
92 | struct list_head *entry = q->out_chunk_list.next; | |
93 | ||
94 | ch = list_entry(entry, struct sctp_chunk, list); | |
95 | list_del_init(entry); | |
1da177e4 | 96 | q->out_qlen -= ch->skb->len; |
79af02c2 | 97 | } |
1da177e4 LT |
98 | return ch; |
99 | } | |
100 | /* Add data chunk to the end of the queue. */ | |
101 | static inline void sctp_outq_tail_data(struct sctp_outq *q, | |
102 | struct sctp_chunk *ch) | |
103 | { | |
79af02c2 | 104 | list_add_tail(&ch->list, &q->out_chunk_list); |
1da177e4 LT |
105 | q->out_qlen += ch->skb->len; |
106 | return; | |
107 | } | |
108 | ||
109 | /* | |
110 | * SFR-CACC algorithm: | |
111 | * D) If count_of_newacks is greater than or equal to 2 | |
112 | * and t was not sent to the current primary then the | |
113 | * sender MUST NOT increment missing report count for t. | |
114 | */ | |
115 | static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, | |
116 | struct sctp_transport *transport, | |
117 | int count_of_newacks) | |
118 | { | |
119 | if (count_of_newacks >=2 && transport != primary) | |
120 | return 1; | |
121 | return 0; | |
122 | } | |
123 | ||
124 | /* | |
125 | * SFR-CACC algorithm: | |
126 | * F) If count_of_newacks is less than 2, let d be the | |
127 | * destination to which t was sent. If cacc_saw_newack | |
128 | * is 0 for destination d, then the sender MUST NOT | |
129 | * increment missing report count for t. | |
130 | */ | |
131 | static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, | |
132 | int count_of_newacks) | |
133 | { | |
134 | if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack) | |
135 | return 1; | |
136 | return 0; | |
137 | } | |
138 | ||
139 | /* | |
140 | * SFR-CACC algorithm: | |
141 | * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD | |
142 | * execute steps C, D, F. | |
143 | * | |
144 | * C has been implemented in sctp_outq_sack | |
145 | */ | |
146 | static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, | |
147 | struct sctp_transport *transport, | |
148 | int count_of_newacks) | |
149 | { | |
150 | if (!primary->cacc.cycling_changeover) { | |
151 | if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks)) | |
152 | return 1; | |
153 | if (sctp_cacc_skip_3_1_f(transport, count_of_newacks)) | |
154 | return 1; | |
155 | return 0; | |
156 | } | |
157 | return 0; | |
158 | } | |
159 | ||
160 | /* | |
161 | * SFR-CACC algorithm: | |
162 | * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less | |
163 | * than next_tsn_at_change of the current primary, then | |
164 | * the sender MUST NOT increment missing report count | |
165 | * for t. | |
166 | */ | |
167 | static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) | |
168 | { | |
169 | if (primary->cacc.cycling_changeover && | |
170 | TSN_lt(tsn, primary->cacc.next_tsn_at_change)) | |
171 | return 1; | |
172 | return 0; | |
173 | } | |
174 | ||
175 | /* | |
176 | * SFR-CACC algorithm: | |
177 | * 3) If the missing report count for TSN t is to be | |
178 | * incremented according to [RFC2960] and | |
179 | * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, | |
180 | * then the sender MUST futher execute steps 3.1 and | |
181 | * 3.2 to determine if the missing report count for | |
182 | * TSN t SHOULD NOT be incremented. | |
183 | * | |
184 | * 3.3) If 3.1 and 3.2 do not dictate that the missing | |
185 | * report count for t should not be incremented, then | |
186 | * the sender SOULD increment missing report count for | |
187 | * t (according to [RFC2960] and [SCTP_STEWART_2002]). | |
188 | */ | |
189 | static inline int sctp_cacc_skip(struct sctp_transport *primary, | |
190 | struct sctp_transport *transport, | |
191 | int count_of_newacks, | |
192 | __u32 tsn) | |
193 | { | |
194 | if (primary->cacc.changeover_active && | |
f64f9e71 JP |
195 | (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) || |
196 | sctp_cacc_skip_3_2(primary, tsn))) | |
1da177e4 LT |
197 | return 1; |
198 | return 0; | |
199 | } | |
200 | ||
201 | /* Initialize an existing sctp_outq. This does the boring stuff. | |
202 | * You still need to define handlers if you really want to DO | |
203 | * something with this structure... | |
204 | */ | |
205 | void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) | |
206 | { | |
207 | q->asoc = asoc; | |
79af02c2 DM |
208 | INIT_LIST_HEAD(&q->out_chunk_list); |
209 | INIT_LIST_HEAD(&q->control_chunk_list); | |
1da177e4 LT |
210 | INIT_LIST_HEAD(&q->retransmit); |
211 | INIT_LIST_HEAD(&q->sacked); | |
212 | INIT_LIST_HEAD(&q->abandoned); | |
213 | ||
62aeaff5 | 214 | q->fast_rtx = 0; |
1da177e4 LT |
215 | q->outstanding_bytes = 0; |
216 | q->empty = 1; | |
217 | q->cork = 0; | |
218 | ||
219 | q->malloced = 0; | |
220 | q->out_qlen = 0; | |
221 | } | |
222 | ||
223 | /* Free the outqueue structure and any related pending chunks. | |
224 | */ | |
225 | void sctp_outq_teardown(struct sctp_outq *q) | |
226 | { | |
227 | struct sctp_transport *transport; | |
9dbc15f0 | 228 | struct list_head *lchunk, *temp; |
79af02c2 | 229 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
230 | |
231 | /* Throw away unacknowledged chunks. */ | |
9dbc15f0 RD |
232 | list_for_each_entry(transport, &q->asoc->peer.transport_addr_list, |
233 | transports) { | |
1da177e4 LT |
234 | while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) { |
235 | chunk = list_entry(lchunk, struct sctp_chunk, | |
236 | transmitted_list); | |
237 | /* Mark as part of a failed message. */ | |
238 | sctp_chunk_fail(chunk, q->error); | |
239 | sctp_chunk_free(chunk); | |
240 | } | |
241 | } | |
242 | ||
243 | /* Throw away chunks that have been gap ACKed. */ | |
244 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
245 | list_del_init(lchunk); | |
246 | chunk = list_entry(lchunk, struct sctp_chunk, | |
247 | transmitted_list); | |
248 | sctp_chunk_fail(chunk, q->error); | |
249 | sctp_chunk_free(chunk); | |
250 | } | |
251 | ||
252 | /* Throw away any chunks in the retransmit queue. */ | |
253 | list_for_each_safe(lchunk, temp, &q->retransmit) { | |
254 | list_del_init(lchunk); | |
255 | chunk = list_entry(lchunk, struct sctp_chunk, | |
256 | transmitted_list); | |
257 | sctp_chunk_fail(chunk, q->error); | |
258 | sctp_chunk_free(chunk); | |
259 | } | |
260 | ||
261 | /* Throw away any chunks that are in the abandoned queue. */ | |
262 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
263 | list_del_init(lchunk); | |
264 | chunk = list_entry(lchunk, struct sctp_chunk, | |
265 | transmitted_list); | |
266 | sctp_chunk_fail(chunk, q->error); | |
267 | sctp_chunk_free(chunk); | |
268 | } | |
269 | ||
270 | /* Throw away any leftover data chunks. */ | |
271 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { | |
272 | ||
273 | /* Mark as send failure. */ | |
274 | sctp_chunk_fail(chunk, q->error); | |
275 | sctp_chunk_free(chunk); | |
276 | } | |
277 | ||
278 | q->error = 0; | |
279 | ||
280 | /* Throw away any leftover control chunks. */ | |
79af02c2 DM |
281 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
282 | list_del_init(&chunk->list); | |
1da177e4 | 283 | sctp_chunk_free(chunk); |
79af02c2 | 284 | } |
1da177e4 LT |
285 | } |
286 | ||
287 | /* Free the outqueue structure and any related pending chunks. */ | |
288 | void sctp_outq_free(struct sctp_outq *q) | |
289 | { | |
290 | /* Throw away leftover chunks. */ | |
291 | sctp_outq_teardown(q); | |
292 | ||
293 | /* If we were kmalloc()'d, free the memory. */ | |
294 | if (q->malloced) | |
295 | kfree(q); | |
296 | } | |
297 | ||
298 | /* Put a new chunk in an sctp_outq. */ | |
299 | int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) | |
300 | { | |
301 | int error = 0; | |
302 | ||
303 | SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n", | |
304 | q, chunk, chunk && chunk->chunk_hdr ? | |
305 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) | |
306 | : "Illegal Chunk"); | |
307 | ||
308 | /* If it is data, queue it up, otherwise, send it | |
309 | * immediately. | |
310 | */ | |
ec7b9519 | 311 | if (sctp_chunk_is_data(chunk)) { |
1da177e4 LT |
312 | /* Is it OK to queue data chunks? */ |
313 | /* From 9. Termination of Association | |
314 | * | |
315 | * When either endpoint performs a shutdown, the | |
316 | * association on each peer will stop accepting new | |
317 | * data from its user and only deliver data in queue | |
318 | * at the time of sending or receiving the SHUTDOWN | |
319 | * chunk. | |
320 | */ | |
321 | switch (q->asoc->state) { | |
322 | case SCTP_STATE_EMPTY: | |
323 | case SCTP_STATE_CLOSED: | |
324 | case SCTP_STATE_SHUTDOWN_PENDING: | |
325 | case SCTP_STATE_SHUTDOWN_SENT: | |
326 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
327 | case SCTP_STATE_SHUTDOWN_ACK_SENT: | |
328 | /* Cannot send after transport endpoint shutdown */ | |
329 | error = -ESHUTDOWN; | |
330 | break; | |
331 | ||
332 | default: | |
333 | SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n", | |
334 | q, chunk, chunk && chunk->chunk_hdr ? | |
335 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) | |
336 | : "Illegal Chunk"); | |
337 | ||
338 | sctp_outq_tail_data(q, chunk); | |
339 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
340 | SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS); | |
341 | else | |
342 | SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS); | |
343 | q->empty = 0; | |
344 | break; | |
3ff50b79 | 345 | } |
1da177e4 | 346 | } else { |
79af02c2 | 347 | list_add_tail(&chunk->list, &q->control_chunk_list); |
1da177e4 LT |
348 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
349 | } | |
350 | ||
351 | if (error < 0) | |
352 | return error; | |
353 | ||
354 | if (!q->cork) | |
355 | error = sctp_outq_flush(q, 0); | |
356 | ||
357 | return error; | |
358 | } | |
359 | ||
360 | /* Insert a chunk into the sorted list based on the TSNs. The retransmit list | |
361 | * and the abandoned list are in ascending order. | |
362 | */ | |
363 | static void sctp_insert_list(struct list_head *head, struct list_head *new) | |
364 | { | |
365 | struct list_head *pos; | |
366 | struct sctp_chunk *nchunk, *lchunk; | |
367 | __u32 ntsn, ltsn; | |
368 | int done = 0; | |
369 | ||
370 | nchunk = list_entry(new, struct sctp_chunk, transmitted_list); | |
371 | ntsn = ntohl(nchunk->subh.data_hdr->tsn); | |
372 | ||
373 | list_for_each(pos, head) { | |
374 | lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); | |
375 | ltsn = ntohl(lchunk->subh.data_hdr->tsn); | |
376 | if (TSN_lt(ntsn, ltsn)) { | |
377 | list_add(new, pos->prev); | |
378 | done = 1; | |
379 | break; | |
380 | } | |
381 | } | |
382 | if (!done) | |
d808ad9a | 383 | list_add_tail(new, head); |
1da177e4 LT |
384 | } |
385 | ||
386 | /* Mark all the eligible packets on a transport for retransmission. */ | |
387 | void sctp_retransmit_mark(struct sctp_outq *q, | |
388 | struct sctp_transport *transport, | |
b6157d8e | 389 | __u8 reason) |
1da177e4 LT |
390 | { |
391 | struct list_head *lchunk, *ltemp; | |
392 | struct sctp_chunk *chunk; | |
393 | ||
394 | /* Walk through the specified transmitted queue. */ | |
395 | list_for_each_safe(lchunk, ltemp, &transport->transmitted) { | |
396 | chunk = list_entry(lchunk, struct sctp_chunk, | |
397 | transmitted_list); | |
398 | ||
399 | /* If the chunk is abandoned, move it to abandoned list. */ | |
400 | if (sctp_chunk_abandoned(chunk)) { | |
401 | list_del_init(lchunk); | |
402 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
403 | |
404 | /* If this chunk has not been previousely acked, | |
405 | * stop considering it 'outstanding'. Our peer | |
406 | * will most likely never see it since it will | |
407 | * not be retransmitted | |
408 | */ | |
409 | if (!chunk->tsn_gap_acked) { | |
31b02e15 VY |
410 | if (chunk->transport) |
411 | chunk->transport->flight_size -= | |
412 | sctp_data_size(chunk); | |
8c4a2d41 VY |
413 | q->outstanding_bytes -= sctp_data_size(chunk); |
414 | q->asoc->peer.rwnd += (sctp_data_size(chunk) + | |
415 | sizeof(struct sk_buff)); | |
416 | } | |
1da177e4 LT |
417 | continue; |
418 | } | |
419 | ||
b6157d8e VY |
420 | /* If we are doing retransmission due to a timeout or pmtu |
421 | * discovery, only the chunks that are not yet acked should | |
422 | * be added to the retransmit queue. | |
1da177e4 | 423 | */ |
b6157d8e | 424 | if ((reason == SCTP_RTXR_FAST_RTX && |
c226ef9b | 425 | (chunk->fast_retransmit == SCTP_NEED_FRTX)) || |
b6157d8e | 426 | (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) { |
1da177e4 LT |
427 | /* RFC 2960 6.2.1 Processing a Received SACK |
428 | * | |
429 | * C) Any time a DATA chunk is marked for | |
430 | * retransmission (via either T3-rtx timer expiration | |
431 | * (Section 6.3.3) or via fast retransmit | |
432 | * (Section 7.2.4)), add the data size of those | |
433 | * chunks to the rwnd. | |
434 | */ | |
cd497885 SS |
435 | q->asoc->peer.rwnd += (sctp_data_size(chunk) + |
436 | sizeof(struct sk_buff)); | |
1da177e4 | 437 | q->outstanding_bytes -= sctp_data_size(chunk); |
31b02e15 VY |
438 | if (chunk->transport) |
439 | transport->flight_size -= sctp_data_size(chunk); | |
1da177e4 LT |
440 | |
441 | /* sctpimpguide-05 Section 2.8.2 | |
442 | * M5) If a T3-rtx timer expires, the | |
443 | * 'TSN.Missing.Report' of all affected TSNs is set | |
444 | * to 0. | |
445 | */ | |
446 | chunk->tsn_missing_report = 0; | |
447 | ||
448 | /* If a chunk that is being used for RTT measurement | |
449 | * has to be retransmitted, we cannot use this chunk | |
450 | * anymore for RTT measurements. Reset rto_pending so | |
451 | * that a new RTT measurement is started when a new | |
452 | * data chunk is sent. | |
453 | */ | |
454 | if (chunk->rtt_in_progress) { | |
455 | chunk->rtt_in_progress = 0; | |
456 | transport->rto_pending = 0; | |
457 | } | |
458 | ||
459 | /* Move the chunk to the retransmit queue. The chunks | |
460 | * on the retransmit queue are always kept in order. | |
461 | */ | |
462 | list_del_init(lchunk); | |
463 | sctp_insert_list(&q->retransmit, lchunk); | |
464 | } | |
465 | } | |
466 | ||
b6157d8e | 467 | SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, " |
1da177e4 | 468 | "cwnd: %d, ssthresh: %d, flight_size: %d, " |
0dc47877 | 469 | "pba: %d\n", __func__, |
b6157d8e | 470 | transport, reason, |
1da177e4 LT |
471 | transport->cwnd, transport->ssthresh, |
472 | transport->flight_size, | |
473 | transport->partial_bytes_acked); | |
474 | ||
475 | } | |
476 | ||
477 | /* Mark all the eligible packets on a transport for retransmission and force | |
478 | * one packet out. | |
479 | */ | |
480 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, | |
481 | sctp_retransmit_reason_t reason) | |
482 | { | |
483 | int error = 0; | |
1da177e4 LT |
484 | |
485 | switch(reason) { | |
486 | case SCTP_RTXR_T3_RTX: | |
ac0b0462 | 487 | SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS); |
1da177e4 LT |
488 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); |
489 | /* Update the retran path if the T3-rtx timer has expired for | |
490 | * the current retran path. | |
491 | */ | |
492 | if (transport == transport->asoc->peer.retran_path) | |
493 | sctp_assoc_update_retran_path(transport->asoc); | |
58fbbed4 NH |
494 | transport->asoc->rtx_data_chunks += |
495 | transport->asoc->unack_data; | |
1da177e4 LT |
496 | break; |
497 | case SCTP_RTXR_FAST_RTX: | |
ac0b0462 | 498 | SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS); |
1da177e4 | 499 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); |
62aeaff5 | 500 | q->fast_rtx = 1; |
1da177e4 LT |
501 | break; |
502 | case SCTP_RTXR_PMTUD: | |
ac0b0462 | 503 | SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS); |
1da177e4 | 504 | break; |
b6157d8e VY |
505 | case SCTP_RTXR_T1_RTX: |
506 | SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS); | |
58fbbed4 | 507 | transport->asoc->init_retries++; |
b6157d8e | 508 | break; |
ac0b0462 SS |
509 | default: |
510 | BUG(); | |
1da177e4 LT |
511 | } |
512 | ||
b6157d8e | 513 | sctp_retransmit_mark(q, transport, reason); |
1da177e4 LT |
514 | |
515 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, | |
516 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by | |
517 | * following the procedures outlined in C1 - C5. | |
518 | */ | |
8b750ce5 VY |
519 | if (reason == SCTP_RTXR_T3_RTX) |
520 | sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); | |
1da177e4 | 521 | |
8b750ce5 VY |
522 | /* Flush the queues only on timeout, since fast_rtx is only |
523 | * triggered during sack processing and the queue | |
524 | * will be flushed at the end. | |
525 | */ | |
526 | if (reason != SCTP_RTXR_FAST_RTX) | |
527 | error = sctp_outq_flush(q, /* rtx_timeout */ 1); | |
1da177e4 LT |
528 | |
529 | if (error) | |
530 | q->asoc->base.sk->sk_err = -error; | |
531 | } | |
532 | ||
533 | /* | |
534 | * Transmit DATA chunks on the retransmit queue. Upon return from | |
535 | * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which | |
536 | * need to be transmitted by the caller. | |
537 | * We assume that pkt->transport has already been set. | |
538 | * | |
539 | * The return value is a normal kernel error return value. | |
540 | */ | |
541 | static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, | |
542 | int rtx_timeout, int *start_timer) | |
543 | { | |
544 | struct list_head *lqueue; | |
1da177e4 LT |
545 | struct sctp_transport *transport = pkt->transport; |
546 | sctp_xmit_t status; | |
547 | struct sctp_chunk *chunk, *chunk1; | |
548 | struct sctp_association *asoc; | |
62aeaff5 | 549 | int fast_rtx; |
1da177e4 | 550 | int error = 0; |
62aeaff5 | 551 | int timer = 0; |
8b750ce5 | 552 | int done = 0; |
1da177e4 LT |
553 | |
554 | asoc = q->asoc; | |
555 | lqueue = &q->retransmit; | |
62aeaff5 | 556 | fast_rtx = q->fast_rtx; |
1da177e4 | 557 | |
8b750ce5 VY |
558 | /* This loop handles time-out retransmissions, fast retransmissions, |
559 | * and retransmissions due to opening of whindow. | |
560 | * | |
561 | * RFC 2960 6.3.3 Handle T3-rtx Expiration | |
1da177e4 LT |
562 | * |
563 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
564 | * outstanding DATA chunks for the address for which the | |
565 | * T3-rtx has expired will fit into a single packet, subject | |
566 | * to the MTU constraint for the path corresponding to the | |
567 | * destination transport address to which the retransmission | |
568 | * is being sent (this may be different from the address for | |
569 | * which the timer expires [see Section 6.4]). Call this value | |
570 | * K. Bundle and retransmit those K DATA chunks in a single | |
571 | * packet to the destination endpoint. | |
572 | * | |
573 | * [Just to be painfully clear, if we are retransmitting | |
574 | * because a timeout just happened, we should send only ONE | |
575 | * packet of retransmitted data.] | |
8b750ce5 VY |
576 | * |
577 | * For fast retransmissions we also send only ONE packet. However, | |
578 | * if we are just flushing the queue due to open window, we'll | |
579 | * try to send as much as possible. | |
1da177e4 | 580 | */ |
8b750ce5 | 581 | list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { |
1da177e4 LT |
582 | |
583 | /* Make sure that Gap Acked TSNs are not retransmitted. A | |
584 | * simple approach is just to move such TSNs out of the | |
585 | * way and into a 'transmitted' queue and skip to the | |
586 | * next chunk. | |
587 | */ | |
588 | if (chunk->tsn_gap_acked) { | |
8b750ce5 VY |
589 | list_del(&chunk->transmitted_list); |
590 | list_add_tail(&chunk->transmitted_list, | |
591 | &transport->transmitted); | |
1da177e4 LT |
592 | continue; |
593 | } | |
594 | ||
8b750ce5 VY |
595 | /* If we are doing fast retransmit, ignore non-fast_rtransmit |
596 | * chunks | |
597 | */ | |
598 | if (fast_rtx && !chunk->fast_retransmit) | |
599 | continue; | |
600 | ||
bc4f841a | 601 | redo: |
1da177e4 LT |
602 | /* Attempt to append this chunk to the packet. */ |
603 | status = sctp_packet_append_chunk(pkt, chunk); | |
604 | ||
605 | switch (status) { | |
606 | case SCTP_XMIT_PMTU_FULL: | |
bc4f841a WY |
607 | if (!pkt->has_data && !pkt->has_cookie_echo) { |
608 | /* If this packet did not contain DATA then | |
609 | * retransmission did not happen, so do it | |
610 | * again. We'll ignore the error here since | |
611 | * control chunks are already freed so there | |
612 | * is nothing we can do. | |
613 | */ | |
614 | sctp_packet_transmit(pkt); | |
615 | goto redo; | |
616 | } | |
617 | ||
1da177e4 | 618 | /* Send this packet. */ |
62aeaff5 | 619 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
620 | |
621 | /* If we are retransmitting, we should only | |
622 | * send a single packet. | |
623 | */ | |
8b750ce5 VY |
624 | if (rtx_timeout || fast_rtx) |
625 | done = 1; | |
1da177e4 | 626 | |
8b750ce5 | 627 | /* Bundle next chunk in the next round. */ |
1da177e4 LT |
628 | break; |
629 | ||
630 | case SCTP_XMIT_RWND_FULL: | |
d808ad9a | 631 | /* Send this packet. */ |
62aeaff5 | 632 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
633 | |
634 | /* Stop sending DATA as there is no more room | |
635 | * at the receiver. | |
636 | */ | |
8b750ce5 | 637 | done = 1; |
1da177e4 LT |
638 | break; |
639 | ||
640 | case SCTP_XMIT_NAGLE_DELAY: | |
d808ad9a | 641 | /* Send this packet. */ |
62aeaff5 | 642 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
643 | |
644 | /* Stop sending DATA because of nagle delay. */ | |
8b750ce5 | 645 | done = 1; |
1da177e4 LT |
646 | break; |
647 | ||
648 | default: | |
649 | /* The append was successful, so add this chunk to | |
650 | * the transmitted list. | |
651 | */ | |
8b750ce5 VY |
652 | list_del(&chunk->transmitted_list); |
653 | list_add_tail(&chunk->transmitted_list, | |
654 | &transport->transmitted); | |
1da177e4 | 655 | |
d808ad9a | 656 | /* Mark the chunk as ineligible for fast retransmit |
1da177e4 LT |
657 | * after it is retransmitted. |
658 | */ | |
c226ef9b NH |
659 | if (chunk->fast_retransmit == SCTP_NEED_FRTX) |
660 | chunk->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 | 661 | |
62aeaff5 VY |
662 | /* Force start T3-rtx timer when fast retransmitting |
663 | * the earliest outstanding TSN | |
664 | */ | |
665 | if (!timer && fast_rtx && | |
666 | ntohl(chunk->subh.data_hdr->tsn) == | |
667 | asoc->ctsn_ack_point + 1) | |
668 | timer = 2; | |
669 | ||
1da177e4 | 670 | q->empty = 0; |
1da177e4 | 671 | break; |
3ff50b79 | 672 | } |
1da177e4 | 673 | |
62aeaff5 VY |
674 | /* Set the timer if there were no errors */ |
675 | if (!error && !timer) | |
676 | timer = 1; | |
677 | ||
8b750ce5 VY |
678 | if (done) |
679 | break; | |
680 | } | |
681 | ||
682 | /* If we are here due to a retransmit timeout or a fast | |
683 | * retransmit and if there are any chunks left in the retransmit | |
684 | * queue that could not fit in the PMTU sized packet, they need | |
685 | * to be marked as ineligible for a subsequent fast retransmit. | |
686 | */ | |
687 | if (rtx_timeout || fast_rtx) { | |
688 | list_for_each_entry(chunk1, lqueue, transmitted_list) { | |
c226ef9b NH |
689 | if (chunk1->fast_retransmit == SCTP_NEED_FRTX) |
690 | chunk1->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 LT |
691 | } |
692 | } | |
693 | ||
62aeaff5 VY |
694 | *start_timer = timer; |
695 | ||
696 | /* Clear fast retransmit hint */ | |
697 | if (fast_rtx) | |
698 | q->fast_rtx = 0; | |
699 | ||
1da177e4 LT |
700 | return error; |
701 | } | |
702 | ||
703 | /* Cork the outqueue so queued chunks are really queued. */ | |
704 | int sctp_outq_uncork(struct sctp_outq *q) | |
705 | { | |
706 | int error = 0; | |
7d54dc68 | 707 | if (q->cork) |
1da177e4 | 708 | q->cork = 0; |
7d54dc68 | 709 | error = sctp_outq_flush(q, 0); |
1da177e4 LT |
710 | return error; |
711 | } | |
712 | ||
2e3216cd | 713 | |
1da177e4 LT |
714 | /* |
715 | * Try to flush an outqueue. | |
716 | * | |
717 | * Description: Send everything in q which we legally can, subject to | |
718 | * congestion limitations. | |
719 | * * Note: This function can be called from multiple contexts so appropriate | |
720 | * locking concerns must be made. Today we use the sock lock to protect | |
721 | * this function. | |
722 | */ | |
abd0b198 | 723 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) |
1da177e4 LT |
724 | { |
725 | struct sctp_packet *packet; | |
726 | struct sctp_packet singleton; | |
727 | struct sctp_association *asoc = q->asoc; | |
728 | __u16 sport = asoc->base.bind_addr.port; | |
729 | __u16 dport = asoc->peer.port; | |
730 | __u32 vtag = asoc->peer.i.init_tag; | |
1da177e4 LT |
731 | struct sctp_transport *transport = NULL; |
732 | struct sctp_transport *new_transport; | |
79af02c2 | 733 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
734 | sctp_xmit_t status; |
735 | int error = 0; | |
736 | int start_timer = 0; | |
2e3216cd | 737 | int one_packet = 0; |
1da177e4 LT |
738 | |
739 | /* These transports have chunks to send. */ | |
740 | struct list_head transport_list; | |
741 | struct list_head *ltransport; | |
742 | ||
743 | INIT_LIST_HEAD(&transport_list); | |
744 | packet = NULL; | |
745 | ||
746 | /* | |
747 | * 6.10 Bundling | |
748 | * ... | |
749 | * When bundling control chunks with DATA chunks, an | |
750 | * endpoint MUST place control chunks first in the outbound | |
751 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
752 | * within a SCTP packet in increasing order of TSN. | |
753 | * ... | |
754 | */ | |
755 | ||
79af02c2 DM |
756 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
757 | list_del_init(&chunk->list); | |
758 | ||
1da177e4 LT |
759 | /* Pick the right transport to use. */ |
760 | new_transport = chunk->transport; | |
761 | ||
762 | if (!new_transport) { | |
a08de64d VY |
763 | /* |
764 | * If we have a prior transport pointer, see if | |
765 | * the destination address of the chunk | |
766 | * matches the destination address of the | |
767 | * current transport. If not a match, then | |
768 | * try to look up the transport with a given | |
769 | * destination address. We do this because | |
770 | * after processing ASCONFs, we may have new | |
771 | * transports created. | |
772 | */ | |
773 | if (transport && | |
774 | sctp_cmp_addr_exact(&chunk->dest, | |
775 | &transport->ipaddr)) | |
776 | new_transport = transport; | |
777 | else | |
778 | new_transport = sctp_assoc_lookup_paddr(asoc, | |
779 | &chunk->dest); | |
780 | ||
781 | /* if we still don't have a new transport, then | |
782 | * use the current active path. | |
783 | */ | |
784 | if (!new_transport) | |
785 | new_transport = asoc->peer.active_path; | |
ad8fec17 SS |
786 | } else if ((new_transport->state == SCTP_INACTIVE) || |
787 | (new_transport->state == SCTP_UNCONFIRMED)) { | |
3f7a87d2 FF |
788 | /* If the chunk is Heartbeat or Heartbeat Ack, |
789 | * send it to chunk->transport, even if it's | |
1da177e4 LT |
790 | * inactive. |
791 | * | |
792 | * 3.3.6 Heartbeat Acknowledgement: | |
d808ad9a | 793 | * ... |
1da177e4 LT |
794 | * A HEARTBEAT ACK is always sent to the source IP |
795 | * address of the IP datagram containing the | |
796 | * HEARTBEAT chunk to which this ack is responding. | |
d808ad9a | 797 | * ... |
a08de64d VY |
798 | * |
799 | * ASCONF_ACKs also must be sent to the source. | |
1da177e4 LT |
800 | */ |
801 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && | |
a08de64d VY |
802 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK && |
803 | chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK) | |
1da177e4 LT |
804 | new_transport = asoc->peer.active_path; |
805 | } | |
806 | ||
807 | /* Are we switching transports? | |
808 | * Take care of transport locks. | |
809 | */ | |
810 | if (new_transport != transport) { | |
811 | transport = new_transport; | |
812 | if (list_empty(&transport->send_ready)) { | |
813 | list_add_tail(&transport->send_ready, | |
814 | &transport_list); | |
815 | } | |
816 | packet = &transport->packet; | |
817 | sctp_packet_config(packet, vtag, | |
818 | asoc->peer.ecn_capable); | |
819 | } | |
820 | ||
821 | switch (chunk->chunk_hdr->type) { | |
822 | /* | |
823 | * 6.10 Bundling | |
824 | * ... | |
825 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
826 | * COMPLETE with any other chunks. [Send them immediately.] | |
827 | */ | |
828 | case SCTP_CID_INIT: | |
829 | case SCTP_CID_INIT_ACK: | |
830 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
831 | sctp_packet_init(&singleton, transport, sport, dport); | |
832 | sctp_packet_config(&singleton, vtag, 0); | |
833 | sctp_packet_append_chunk(&singleton, chunk); | |
834 | error = sctp_packet_transmit(&singleton); | |
835 | if (error < 0) | |
836 | return error; | |
837 | break; | |
838 | ||
839 | case SCTP_CID_ABORT: | |
f4ad85ca GJ |
840 | if (sctp_test_T_bit(chunk)) { |
841 | packet->vtag = asoc->c.my_vtag; | |
842 | } | |
2e3216cd VY |
843 | /* The following chunks are "response" chunks, i.e. |
844 | * they are generated in response to something we | |
845 | * received. If we are sending these, then we can | |
846 | * send only 1 packet containing these chunks. | |
847 | */ | |
1da177e4 | 848 | case SCTP_CID_HEARTBEAT_ACK: |
1da177e4 | 849 | case SCTP_CID_SHUTDOWN_ACK: |
1da177e4 | 850 | case SCTP_CID_COOKIE_ACK: |
2e3216cd VY |
851 | case SCTP_CID_COOKIE_ECHO: |
852 | case SCTP_CID_ERROR: | |
1da177e4 | 853 | case SCTP_CID_ECN_CWR: |
1da177e4 | 854 | case SCTP_CID_ASCONF_ACK: |
2e3216cd VY |
855 | one_packet = 1; |
856 | /* Fall throught */ | |
857 | ||
858 | case SCTP_CID_SACK: | |
859 | case SCTP_CID_HEARTBEAT: | |
860 | case SCTP_CID_SHUTDOWN: | |
861 | case SCTP_CID_ECN_ECNE: | |
862 | case SCTP_CID_ASCONF: | |
1da177e4 | 863 | case SCTP_CID_FWD_TSN: |
2e3216cd VY |
864 | status = sctp_packet_transmit_chunk(packet, chunk, |
865 | one_packet); | |
866 | if (status != SCTP_XMIT_OK) { | |
867 | /* put the chunk back */ | |
868 | list_add(&chunk->list, &q->control_chunk_list); | |
bd69b981 WY |
869 | } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) { |
870 | /* PR-SCTP C5) If a FORWARD TSN is sent, the | |
871 | * sender MUST assure that at least one T3-rtx | |
872 | * timer is running. | |
873 | */ | |
874 | sctp_transport_reset_timers(transport, 0); | |
2e3216cd | 875 | } |
1da177e4 LT |
876 | break; |
877 | ||
878 | default: | |
879 | /* We built a chunk with an illegal type! */ | |
880 | BUG(); | |
3ff50b79 | 881 | } |
1da177e4 LT |
882 | } |
883 | ||
884 | /* Is it OK to send data chunks? */ | |
885 | switch (asoc->state) { | |
886 | case SCTP_STATE_COOKIE_ECHOED: | |
887 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
888 | * chunk. | |
889 | */ | |
890 | if (!packet || !packet->has_cookie_echo) | |
891 | break; | |
892 | ||
893 | /* fallthru */ | |
894 | case SCTP_STATE_ESTABLISHED: | |
895 | case SCTP_STATE_SHUTDOWN_PENDING: | |
896 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
897 | /* | |
898 | * RFC 2960 6.1 Transmission of DATA Chunks | |
899 | * | |
900 | * C) When the time comes for the sender to transmit, | |
901 | * before sending new DATA chunks, the sender MUST | |
902 | * first transmit any outstanding DATA chunks which | |
903 | * are marked for retransmission (limited by the | |
904 | * current cwnd). | |
905 | */ | |
906 | if (!list_empty(&q->retransmit)) { | |
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) | |
62aeaff5 VY |
927 | sctp_transport_reset_timers(transport, |
928 | start_timer-1); | |
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 SS |
977 | ((new_transport->state == SCTP_INACTIVE) || |
978 | (new_transport->state == SCTP_UNCONFIRMED))) | |
1da177e4 LT |
979 | new_transport = asoc->peer.active_path; |
980 | ||
981 | /* Change packets if necessary. */ | |
982 | if (new_transport != transport) { | |
983 | transport = new_transport; | |
984 | ||
985 | /* Schedule to have this transport's | |
986 | * packet flushed. | |
987 | */ | |
988 | if (list_empty(&transport->send_ready)) { | |
989 | list_add_tail(&transport->send_ready, | |
990 | &transport_list); | |
991 | } | |
992 | ||
993 | packet = &transport->packet; | |
994 | sctp_packet_config(packet, vtag, | |
995 | asoc->peer.ecn_capable); | |
46d5a808 VY |
996 | /* We've switched transports, so apply the |
997 | * Burst limit to the new transport. | |
998 | */ | |
999 | sctp_transport_burst_limited(transport); | |
1da177e4 LT |
1000 | } |
1001 | ||
1002 | SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ", | |
1003 | q, chunk, | |
1004 | chunk && chunk->chunk_hdr ? | |
1005 | sctp_cname(SCTP_ST_CHUNK( | |
1006 | chunk->chunk_hdr->type)) | |
1007 | : "Illegal Chunk"); | |
1008 | ||
1009 | SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head " | |
1010 | "%p skb->users %d.\n", | |
1011 | ntohl(chunk->subh.data_hdr->tsn), | |
1012 | chunk->skb ?chunk->skb->head : NULL, | |
1013 | chunk->skb ? | |
1014 | atomic_read(&chunk->skb->users) : -1); | |
1015 | ||
1016 | /* Add the chunk to the packet. */ | |
2e3216cd | 1017 | status = sctp_packet_transmit_chunk(packet, chunk, 0); |
1da177e4 LT |
1018 | |
1019 | switch (status) { | |
1020 | case SCTP_XMIT_PMTU_FULL: | |
1021 | case SCTP_XMIT_RWND_FULL: | |
1022 | case SCTP_XMIT_NAGLE_DELAY: | |
1023 | /* We could not append this chunk, so put | |
1024 | * the chunk back on the output queue. | |
1025 | */ | |
1026 | SCTP_DEBUG_PRINTK("sctp_outq_flush: could " | |
1027 | "not transmit TSN: 0x%x, status: %d\n", | |
1028 | ntohl(chunk->subh.data_hdr->tsn), | |
1029 | status); | |
1030 | sctp_outq_head_data(q, chunk); | |
1031 | goto sctp_flush_out; | |
1032 | break; | |
1033 | ||
1034 | case SCTP_XMIT_OK: | |
b93d6471 WY |
1035 | /* The sender is in the SHUTDOWN-PENDING state, |
1036 | * The sender MAY set the I-bit in the DATA | |
1037 | * chunk header. | |
1038 | */ | |
1039 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) | |
1040 | chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; | |
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 | ||
6574df9a | 1061 | sctp_transport_reset_timers(transport, 0); |
1da177e4 LT |
1062 | |
1063 | q->empty = 0; | |
1064 | ||
1065 | /* Only let one DATA chunk get bundled with a | |
1066 | * COOKIE-ECHO chunk. | |
1067 | */ | |
1068 | if (packet->has_cookie_echo) | |
1069 | goto sctp_flush_out; | |
1070 | } | |
1071 | break; | |
1072 | ||
1073 | default: | |
1074 | /* Do nothing. */ | |
1075 | break; | |
1076 | } | |
1077 | ||
1078 | sctp_flush_out: | |
1079 | ||
1080 | /* Before returning, examine all the transports touched in | |
1081 | * this call. Right now, we bluntly force clear all the | |
1082 | * transports. Things might change after we implement Nagle. | |
1083 | * But such an examination is still required. | |
1084 | * | |
1085 | * --xguo | |
1086 | */ | |
1087 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) { | |
1088 | struct sctp_transport *t = list_entry(ltransport, | |
1089 | struct sctp_transport, | |
1090 | send_ready); | |
1091 | packet = &t->packet; | |
1092 | if (!sctp_packet_empty(packet)) | |
1093 | error = sctp_packet_transmit(packet); | |
46d5a808 VY |
1094 | |
1095 | /* Clear the burst limited state, if any */ | |
1096 | sctp_transport_burst_reset(t); | |
1da177e4 LT |
1097 | } |
1098 | ||
1099 | return error; | |
1100 | } | |
1101 | ||
1102 | /* Update unack_data based on the incoming SACK chunk */ | |
1103 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
1104 | struct sctp_sackhdr *sack) | |
1105 | { | |
1106 | sctp_sack_variable_t *frags; | |
1107 | __u16 unack_data; | |
1108 | int i; | |
1109 | ||
1110 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
1111 | ||
1112 | frags = sack->variable; | |
1113 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
1114 | unack_data -= ((ntohs(frags[i].gab.end) - | |
1115 | ntohs(frags[i].gab.start) + 1)); | |
1116 | } | |
1117 | ||
1118 | assoc->unack_data = unack_data; | |
1119 | } | |
1120 | ||
1121 | /* Return the highest new tsn that is acknowledged by the given SACK chunk. */ | |
1122 | static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack, | |
1123 | struct sctp_association *asoc) | |
1124 | { | |
1da177e4 LT |
1125 | struct sctp_transport *transport; |
1126 | struct sctp_chunk *chunk; | |
1127 | __u32 highest_new_tsn, tsn; | |
1128 | struct list_head *transport_list = &asoc->peer.transport_addr_list; | |
1129 | ||
1130 | highest_new_tsn = ntohl(sack->cum_tsn_ack); | |
1131 | ||
9dbc15f0 RD |
1132 | list_for_each_entry(transport, transport_list, transports) { |
1133 | list_for_each_entry(chunk, &transport->transmitted, | |
1134 | transmitted_list) { | |
1da177e4 LT |
1135 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1136 | ||
1137 | if (!chunk->tsn_gap_acked && | |
1138 | TSN_lt(highest_new_tsn, tsn) && | |
1139 | sctp_acked(sack, tsn)) | |
1140 | highest_new_tsn = tsn; | |
1141 | } | |
1142 | } | |
1143 | ||
1144 | return highest_new_tsn; | |
1145 | } | |
1146 | ||
1147 | /* This is where we REALLY process a SACK. | |
1148 | * | |
1149 | * Process the SACK against the outqueue. Mostly, this just frees | |
1150 | * things off the transmitted queue. | |
1151 | */ | |
1152 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) | |
1153 | { | |
1154 | struct sctp_association *asoc = q->asoc; | |
1155 | struct sctp_transport *transport; | |
1156 | struct sctp_chunk *tchunk = NULL; | |
9dbc15f0 | 1157 | struct list_head *lchunk, *transport_list, *temp; |
1da177e4 LT |
1158 | sctp_sack_variable_t *frags = sack->variable; |
1159 | __u32 sack_ctsn, ctsn, tsn; | |
1160 | __u32 highest_tsn, highest_new_tsn; | |
1161 | __u32 sack_a_rwnd; | |
1162 | unsigned outstanding; | |
1163 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1164 | int count_of_newacks = 0; | |
2cd9b822 | 1165 | int gap_ack_blocks; |
1da177e4 LT |
1166 | |
1167 | /* Grab the association's destination address list. */ | |
1168 | transport_list = &asoc->peer.transport_addr_list; | |
1169 | ||
1170 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
2cd9b822 | 1171 | gap_ack_blocks = ntohs(sack->num_gap_ack_blocks); |
1da177e4 LT |
1172 | /* |
1173 | * SFR-CACC algorithm: | |
1174 | * On receipt of a SACK the sender SHOULD execute the | |
1175 | * following statements. | |
1176 | * | |
1177 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1178 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1179 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1180 | * all destinations. | |
1da177e4 LT |
1181 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
1182 | * is set the receiver of the SACK MUST take the following actions: | |
1183 | * | |
1184 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1185 | * addresses. | |
ab5216a5 VY |
1186 | * |
1187 | * Only bother if changeover_active is set. Otherwise, this is | |
1188 | * totally suboptimal to do on every SACK. | |
1da177e4 | 1189 | */ |
ab5216a5 VY |
1190 | if (primary->cacc.changeover_active) { |
1191 | u8 clear_cycling = 0; | |
1192 | ||
1193 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1194 | primary->cacc.changeover_active = 0; | |
1195 | clear_cycling = 1; | |
1196 | } | |
1197 | ||
1198 | if (clear_cycling || gap_ack_blocks) { | |
1199 | list_for_each_entry(transport, transport_list, | |
1200 | transports) { | |
1201 | if (clear_cycling) | |
1202 | transport->cacc.cycling_changeover = 0; | |
1203 | if (gap_ack_blocks) | |
1204 | transport->cacc.cacc_saw_newack = 0; | |
1205 | } | |
1da177e4 LT |
1206 | } |
1207 | } | |
1208 | ||
1209 | /* Get the highest TSN in the sack. */ | |
1210 | highest_tsn = sack_ctsn; | |
2cd9b822 VY |
1211 | if (gap_ack_blocks) |
1212 | highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); | |
1da177e4 LT |
1213 | |
1214 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) { | |
1215 | highest_new_tsn = highest_tsn; | |
1216 | asoc->highest_sacked = highest_tsn; | |
1217 | } else { | |
1218 | highest_new_tsn = sctp_highest_new_tsn(sack, asoc); | |
1219 | } | |
1220 | ||
2cd9b822 | 1221 | |
1da177e4 LT |
1222 | /* Run through the retransmit queue. Credit bytes received |
1223 | * and free those chunks that we can. | |
1224 | */ | |
1225 | sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn); | |
1da177e4 LT |
1226 | |
1227 | /* Run through the transmitted queue. | |
1228 | * Credit bytes received and free those chunks which we can. | |
1229 | * | |
1230 | * This is a MASSIVE candidate for optimization. | |
1231 | */ | |
9dbc15f0 | 1232 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 LT |
1233 | sctp_check_transmitted(q, &transport->transmitted, |
1234 | transport, sack, highest_new_tsn); | |
1235 | /* | |
1236 | * SFR-CACC algorithm: | |
1237 | * C) Let count_of_newacks be the number of | |
1238 | * destinations for which cacc_saw_newack is set. | |
1239 | */ | |
1240 | if (transport->cacc.cacc_saw_newack) | |
1241 | count_of_newacks ++; | |
1242 | } | |
1243 | ||
2cd9b822 | 1244 | if (gap_ack_blocks) { |
2cd9b822 VY |
1245 | list_for_each_entry(transport, transport_list, transports) |
1246 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1247 | highest_new_tsn, count_of_newacks); | |
1da177e4 LT |
1248 | } |
1249 | ||
1250 | /* Move the Cumulative TSN Ack Point if appropriate. */ | |
1251 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) | |
1252 | asoc->ctsn_ack_point = sack_ctsn; | |
1253 | ||
1254 | /* Update unack_data field in the assoc. */ | |
1255 | sctp_sack_update_unack_data(asoc, sack); | |
1256 | ||
1257 | ctsn = asoc->ctsn_ack_point; | |
1258 | ||
1259 | /* Throw away stuff rotting on the sack queue. */ | |
1260 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1261 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1262 | transmitted_list); | |
1263 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
5f9646c3 VY |
1264 | if (TSN_lte(tsn, ctsn)) { |
1265 | list_del_init(&tchunk->transmitted_list); | |
1da177e4 | 1266 | sctp_chunk_free(tchunk); |
5f9646c3 | 1267 | } |
1da177e4 LT |
1268 | } |
1269 | ||
1270 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1271 | * number of bytes still outstanding after processing the | |
1272 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1273 | */ | |
1274 | ||
1275 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
1276 | outstanding = q->outstanding_bytes; | |
1277 | ||
1278 | if (outstanding < sack_a_rwnd) | |
1279 | sack_a_rwnd -= outstanding; | |
1280 | else | |
1281 | sack_a_rwnd = 0; | |
1282 | ||
1283 | asoc->peer.rwnd = sack_a_rwnd; | |
1284 | ||
1285 | sctp_generate_fwdtsn(q, sack_ctsn); | |
1286 | ||
1287 | SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n", | |
0dc47877 | 1288 | __func__, sack_ctsn); |
1da177e4 LT |
1289 | SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, " |
1290 | "%p is 0x%x. Adv peer ack point: 0x%x\n", | |
0dc47877 | 1291 | __func__, asoc, ctsn, asoc->adv_peer_ack_point); |
1da177e4 LT |
1292 | |
1293 | /* See if all chunks are acked. | |
1294 | * Make sure the empty queue handler will get run later. | |
1295 | */ | |
79af02c2 | 1296 | q->empty = (list_empty(&q->out_chunk_list) && |
79af02c2 | 1297 | list_empty(&q->retransmit)); |
1da177e4 LT |
1298 | if (!q->empty) |
1299 | goto finish; | |
1300 | ||
9dbc15f0 | 1301 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 LT |
1302 | q->empty = q->empty && list_empty(&transport->transmitted); |
1303 | if (!q->empty) | |
1304 | goto finish; | |
1305 | } | |
1306 | ||
1307 | SCTP_DEBUG_PRINTK("sack queue is empty.\n"); | |
1308 | finish: | |
1309 | return q->empty; | |
1310 | } | |
1311 | ||
1312 | /* Is the outqueue empty? */ | |
1313 | int sctp_outq_is_empty(const struct sctp_outq *q) | |
1314 | { | |
1315 | return q->empty; | |
1316 | } | |
1317 | ||
1318 | /******************************************************************** | |
1319 | * 2nd Level Abstractions | |
1320 | ********************************************************************/ | |
1321 | ||
1322 | /* Go through a transport's transmitted list or the association's retransmit | |
1323 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1324 | * The retransmit list will not have an associated transport. | |
1325 | * | |
1326 | * I added coherent debug information output. --xguo | |
1327 | * | |
1328 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1329 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1330 | * KEPT TSN6-TSN7, etc. | |
1331 | */ | |
1332 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1333 | struct list_head *transmitted_queue, | |
1334 | struct sctp_transport *transport, | |
1335 | struct sctp_sackhdr *sack, | |
1336 | __u32 highest_new_tsn_in_sack) | |
1337 | { | |
1338 | struct list_head *lchunk; | |
1339 | struct sctp_chunk *tchunk; | |
1340 | struct list_head tlist; | |
1341 | __u32 tsn; | |
1342 | __u32 sack_ctsn; | |
1343 | __u32 rtt; | |
1344 | __u8 restart_timer = 0; | |
1345 | int bytes_acked = 0; | |
31b02e15 | 1346 | int migrate_bytes = 0; |
1da177e4 LT |
1347 | |
1348 | /* These state variables are for coherent debug output. --xguo */ | |
1349 | ||
1350 | #if SCTP_DEBUG | |
1351 | __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */ | |
1352 | __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */ | |
1353 | __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */ | |
1354 | __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */ | |
1355 | ||
1356 | /* 0 : The last TSN was ACKed. | |
1357 | * 1 : The last TSN was NOT ACKed (i.e. KEPT). | |
1358 | * -1: We need to initialize. | |
1359 | */ | |
1360 | int dbg_prt_state = -1; | |
1361 | #endif /* SCTP_DEBUG */ | |
1362 | ||
1363 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
1364 | ||
1365 | INIT_LIST_HEAD(&tlist); | |
1366 | ||
1367 | /* The while loop will skip empty transmitted queues. */ | |
1368 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1369 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1370 | transmitted_list); | |
1371 | ||
1372 | if (sctp_chunk_abandoned(tchunk)) { | |
1373 | /* Move the chunk to abandoned list. */ | |
1374 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
1375 | |
1376 | /* If this chunk has not been acked, stop | |
1377 | * considering it as 'outstanding'. | |
1378 | */ | |
1379 | if (!tchunk->tsn_gap_acked) { | |
31b02e15 VY |
1380 | if (tchunk->transport) |
1381 | tchunk->transport->flight_size -= | |
1382 | sctp_data_size(tchunk); | |
8c4a2d41 VY |
1383 | q->outstanding_bytes -= sctp_data_size(tchunk); |
1384 | } | |
1da177e4 LT |
1385 | continue; |
1386 | } | |
1387 | ||
1388 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1389 | if (sctp_acked(sack, tsn)) { | |
1390 | /* If this queue is the retransmit queue, the | |
1391 | * retransmit timer has already reclaimed | |
1392 | * the outstanding bytes for this chunk, so only | |
1393 | * count bytes associated with a transport. | |
1394 | */ | |
1395 | if (transport) { | |
1396 | /* If this chunk is being used for RTT | |
1397 | * measurement, calculate the RTT and update | |
1398 | * the RTO using this value. | |
1399 | * | |
1400 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1401 | * MUST NOT be made using packets that were | |
1402 | * retransmitted (and thus for which it is | |
1403 | * ambiguous whether the reply was for the | |
1404 | * first instance of the packet or a later | |
1405 | * instance). | |
1406 | */ | |
d808ad9a | 1407 | if (!tchunk->tsn_gap_acked && |
1da177e4 | 1408 | tchunk->rtt_in_progress) { |
4c9f5d53 | 1409 | tchunk->rtt_in_progress = 0; |
1da177e4 LT |
1410 | rtt = jiffies - tchunk->sent_at; |
1411 | sctp_transport_update_rto(transport, | |
1412 | rtt); | |
1413 | } | |
1414 | } | |
31b02e15 VY |
1415 | |
1416 | /* If the chunk hasn't been marked as ACKED, | |
1417 | * mark it and account bytes_acked if the | |
1418 | * chunk had a valid transport (it will not | |
1419 | * have a transport if ASCONF had deleted it | |
1420 | * while DATA was outstanding). | |
1421 | */ | |
1422 | if (!tchunk->tsn_gap_acked) { | |
1423 | tchunk->tsn_gap_acked = 1; | |
1424 | bytes_acked += sctp_data_size(tchunk); | |
1425 | if (!tchunk->transport) | |
1426 | migrate_bytes += sctp_data_size(tchunk); | |
1427 | } | |
1428 | ||
d808ad9a | 1429 | if (TSN_lte(tsn, sack_ctsn)) { |
1da177e4 LT |
1430 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
1431 | * | |
1432 | * R3) Whenever a SACK is received | |
1433 | * that acknowledges the DATA chunk | |
1434 | * with the earliest outstanding TSN | |
1435 | * for that address, restart T3-rtx | |
1436 | * timer for that address with its | |
1437 | * current RTO. | |
1438 | */ | |
1439 | restart_timer = 1; | |
1440 | ||
1441 | if (!tchunk->tsn_gap_acked) { | |
1da177e4 LT |
1442 | /* |
1443 | * SFR-CACC algorithm: | |
1444 | * 2) If the SACK contains gap acks | |
1445 | * and the flag CHANGEOVER_ACTIVE is | |
1446 | * set the receiver of the SACK MUST | |
1447 | * take the following action: | |
1448 | * | |
1449 | * B) For each TSN t being acked that | |
1450 | * has not been acked in any SACK so | |
1451 | * far, set cacc_saw_newack to 1 for | |
1452 | * the destination that the TSN was | |
1453 | * sent to. | |
1454 | */ | |
1455 | if (transport && | |
1456 | sack->num_gap_ack_blocks && | |
1457 | q->asoc->peer.primary_path->cacc. | |
1458 | changeover_active) | |
1459 | transport->cacc.cacc_saw_newack | |
1460 | = 1; | |
1461 | } | |
1462 | ||
1463 | list_add_tail(&tchunk->transmitted_list, | |
1464 | &q->sacked); | |
1465 | } else { | |
1466 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1467 | * M2) Each time a SACK arrives reporting | |
1468 | * 'Stray DATA chunk(s)' record the highest TSN | |
1469 | * reported as newly acknowledged, call this | |
1470 | * value 'HighestTSNinSack'. A newly | |
1471 | * acknowledged DATA chunk is one not | |
1472 | * previously acknowledged in a SACK. | |
1473 | * | |
1474 | * When the SCTP sender of data receives a SACK | |
1475 | * chunk that acknowledges, for the first time, | |
1476 | * the receipt of a DATA chunk, all the still | |
1477 | * unacknowledged DATA chunks whose TSN is | |
1478 | * older than that newly acknowledged DATA | |
1479 | * chunk, are qualified as 'Stray DATA chunks'. | |
1480 | */ | |
1da177e4 LT |
1481 | list_add_tail(lchunk, &tlist); |
1482 | } | |
1483 | ||
1484 | #if SCTP_DEBUG | |
1485 | switch (dbg_prt_state) { | |
1486 | case 0: /* last TSN was ACKed */ | |
1487 | if (dbg_last_ack_tsn + 1 == tsn) { | |
1488 | /* This TSN belongs to the | |
1489 | * current ACK range. | |
1490 | */ | |
1491 | break; | |
1492 | } | |
1493 | ||
1494 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
1495 | /* Display the end of the | |
1496 | * current range. | |
1497 | */ | |
1498 | SCTP_DEBUG_PRINTK("-%08x", | |
1499 | dbg_last_ack_tsn); | |
1500 | } | |
1501 | ||
1502 | /* Start a new range. */ | |
1503 | SCTP_DEBUG_PRINTK(",%08x", tsn); | |
1504 | dbg_ack_tsn = tsn; | |
1505 | break; | |
1506 | ||
1507 | case 1: /* The last TSN was NOT ACKed. */ | |
1508 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
1509 | /* Display the end of current range. */ | |
1510 | SCTP_DEBUG_PRINTK("-%08x", | |
1511 | dbg_last_kept_tsn); | |
1512 | } | |
1513 | ||
1514 | SCTP_DEBUG_PRINTK("\n"); | |
1515 | ||
1516 | /* FALL THROUGH... */ | |
1517 | default: | |
1518 | /* This is the first-ever TSN we examined. */ | |
1519 | /* Start a new range of ACK-ed TSNs. */ | |
1520 | SCTP_DEBUG_PRINTK("ACKed: %08x", tsn); | |
1521 | dbg_prt_state = 0; | |
1522 | dbg_ack_tsn = tsn; | |
3ff50b79 | 1523 | } |
1da177e4 LT |
1524 | |
1525 | dbg_last_ack_tsn = tsn; | |
1526 | #endif /* SCTP_DEBUG */ | |
1527 | ||
1528 | } else { | |
1529 | if (tchunk->tsn_gap_acked) { | |
1530 | SCTP_DEBUG_PRINTK("%s: Receiver reneged on " | |
1531 | "data TSN: 0x%x\n", | |
0dc47877 | 1532 | __func__, |
1da177e4 LT |
1533 | tsn); |
1534 | tchunk->tsn_gap_acked = 0; | |
1535 | ||
31b02e15 VY |
1536 | if (tchunk->transport) |
1537 | bytes_acked -= sctp_data_size(tchunk); | |
1da177e4 LT |
1538 | |
1539 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1540 | * | |
1541 | * R4) Whenever a SACK is received missing a | |
1542 | * TSN that was previously acknowledged via a | |
1543 | * Gap Ack Block, start T3-rtx for the | |
1544 | * destination address to which the DATA | |
1545 | * chunk was originally | |
1546 | * transmitted if it is not already running. | |
1547 | */ | |
1548 | restart_timer = 1; | |
1549 | } | |
1550 | ||
1551 | list_add_tail(lchunk, &tlist); | |
1552 | ||
1553 | #if SCTP_DEBUG | |
1554 | /* See the above comments on ACK-ed TSNs. */ | |
1555 | switch (dbg_prt_state) { | |
1556 | case 1: | |
1557 | if (dbg_last_kept_tsn + 1 == tsn) | |
1558 | break; | |
1559 | ||
1560 | if (dbg_last_kept_tsn != dbg_kept_tsn) | |
1561 | SCTP_DEBUG_PRINTK("-%08x", | |
1562 | dbg_last_kept_tsn); | |
1563 | ||
1564 | SCTP_DEBUG_PRINTK(",%08x", tsn); | |
1565 | dbg_kept_tsn = tsn; | |
1566 | break; | |
1567 | ||
1568 | case 0: | |
1569 | if (dbg_last_ack_tsn != dbg_ack_tsn) | |
1570 | SCTP_DEBUG_PRINTK("-%08x", | |
1571 | dbg_last_ack_tsn); | |
1572 | SCTP_DEBUG_PRINTK("\n"); | |
1573 | ||
1574 | /* FALL THROUGH... */ | |
1575 | default: | |
1576 | SCTP_DEBUG_PRINTK("KEPT: %08x",tsn); | |
1577 | dbg_prt_state = 1; | |
1578 | dbg_kept_tsn = tsn; | |
3ff50b79 | 1579 | } |
1da177e4 LT |
1580 | |
1581 | dbg_last_kept_tsn = tsn; | |
1582 | #endif /* SCTP_DEBUG */ | |
1583 | } | |
1584 | } | |
1585 | ||
1586 | #if SCTP_DEBUG | |
1587 | /* Finish off the last range, displaying its ending TSN. */ | |
1588 | switch (dbg_prt_state) { | |
1589 | case 0: | |
1590 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
1591 | SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn); | |
1592 | } else { | |
1593 | SCTP_DEBUG_PRINTK("\n"); | |
1594 | } | |
1595 | break; | |
1596 | ||
1597 | case 1: | |
1598 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
1599 | SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn); | |
1600 | } else { | |
1601 | SCTP_DEBUG_PRINTK("\n"); | |
1602 | } | |
3ff50b79 | 1603 | } |
1da177e4 LT |
1604 | #endif /* SCTP_DEBUG */ |
1605 | if (transport) { | |
1606 | if (bytes_acked) { | |
31b02e15 VY |
1607 | /* We may have counted DATA that was migrated |
1608 | * to this transport due to DEL-IP operation. | |
1609 | * Subtract those bytes, since the were never | |
1610 | * send on this transport and shouldn't be | |
1611 | * credited to this transport. | |
1612 | */ | |
1613 | bytes_acked -= migrate_bytes; | |
1614 | ||
1da177e4 LT |
1615 | /* 8.2. When an outstanding TSN is acknowledged, |
1616 | * the endpoint shall clear the error counter of | |
1617 | * the destination transport address to which the | |
1618 | * DATA chunk was last sent. | |
1619 | * The association's overall error counter is | |
1620 | * also cleared. | |
1621 | */ | |
1622 | transport->error_count = 0; | |
1623 | transport->asoc->overall_error_count = 0; | |
1624 | ||
1625 | /* Mark the destination transport address as | |
1626 | * active if it is not so marked. | |
1627 | */ | |
ad8fec17 SS |
1628 | if ((transport->state == SCTP_INACTIVE) || |
1629 | (transport->state == SCTP_UNCONFIRMED)) { | |
1da177e4 LT |
1630 | sctp_assoc_control_transport( |
1631 | transport->asoc, | |
1632 | transport, | |
1633 | SCTP_TRANSPORT_UP, | |
1634 | SCTP_RECEIVED_SACK); | |
1635 | } | |
1636 | ||
1637 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1638 | bytes_acked); | |
1639 | ||
1640 | transport->flight_size -= bytes_acked; | |
8b73a07c GJ |
1641 | if (transport->flight_size == 0) |
1642 | transport->partial_bytes_acked = 0; | |
31b02e15 | 1643 | q->outstanding_bytes -= bytes_acked + migrate_bytes; |
1da177e4 LT |
1644 | } else { |
1645 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1646 | * When a sender is doing zero window probing, it | |
1647 | * should not timeout the association if it continues | |
1648 | * to receive new packets from the receiver. The | |
1649 | * reason is that the receiver MAY keep its window | |
1650 | * closed for an indefinite time. | |
1651 | * A sender is doing zero window probing when the | |
1652 | * receiver's advertised window is zero, and there is | |
1653 | * only one data chunk in flight to the receiver. | |
1654 | */ | |
1655 | if (!q->asoc->peer.rwnd && | |
1656 | !list_empty(&tlist) && | |
1657 | (sack_ctsn+2 == q->asoc->next_tsn)) { | |
1658 | SCTP_DEBUG_PRINTK("%s: SACK received for zero " | |
1659 | "window probe: %u\n", | |
0dc47877 | 1660 | __func__, sack_ctsn); |
1da177e4 LT |
1661 | q->asoc->overall_error_count = 0; |
1662 | transport->error_count = 0; | |
1663 | } | |
1664 | } | |
1665 | ||
1666 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1667 | * | |
1668 | * R2) Whenever all outstanding data sent to an address have | |
1669 | * been acknowledged, turn off the T3-rtx timer of that | |
1670 | * address. | |
1671 | */ | |
1672 | if (!transport->flight_size) { | |
1673 | if (timer_pending(&transport->T3_rtx_timer) && | |
1674 | del_timer(&transport->T3_rtx_timer)) { | |
1675 | sctp_transport_put(transport); | |
1676 | } | |
1677 | } else if (restart_timer) { | |
1678 | if (!mod_timer(&transport->T3_rtx_timer, | |
1679 | jiffies + transport->rto)) | |
1680 | sctp_transport_hold(transport); | |
1681 | } | |
1682 | } | |
1683 | ||
1684 | list_splice(&tlist, transmitted_queue); | |
1685 | } | |
1686 | ||
1687 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1688 | static void sctp_mark_missing(struct sctp_outq *q, | |
1689 | struct list_head *transmitted_queue, | |
1690 | struct sctp_transport *transport, | |
1691 | __u32 highest_new_tsn_in_sack, | |
1692 | int count_of_newacks) | |
1693 | { | |
1694 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1695 | __u32 tsn; |
1696 | char do_fast_retransmit = 0; | |
1697 | struct sctp_transport *primary = q->asoc->peer.primary_path; | |
1698 | ||
9dbc15f0 | 1699 | list_for_each_entry(chunk, transmitted_queue, transmitted_list) { |
1da177e4 | 1700 | |
1da177e4 LT |
1701 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1702 | ||
1703 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1704 | * 'Unacknowledged TSN's', if the TSN number of an | |
1705 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1706 | * value, increment the 'TSN.Missing.Report' count on that | |
1707 | * chunk if it has NOT been fast retransmitted or marked for | |
1708 | * fast retransmit already. | |
1709 | */ | |
c226ef9b | 1710 | if (chunk->fast_retransmit == SCTP_CAN_FRTX && |
1da177e4 LT |
1711 | !chunk->tsn_gap_acked && |
1712 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1713 | ||
1714 | /* SFR-CACC may require us to skip marking | |
1715 | * this chunk as missing. | |
1716 | */ | |
1717 | if (!transport || !sctp_cacc_skip(primary, transport, | |
1718 | count_of_newacks, tsn)) { | |
1719 | chunk->tsn_missing_report++; | |
1720 | ||
1721 | SCTP_DEBUG_PRINTK( | |
1722 | "%s: TSN 0x%x missing counter: %d\n", | |
0dc47877 | 1723 | __func__, tsn, |
1da177e4 LT |
1724 | chunk->tsn_missing_report); |
1725 | } | |
1726 | } | |
1727 | /* | |
1728 | * M4) If any DATA chunk is found to have a | |
1729 | * 'TSN.Missing.Report' | |
27852c26 | 1730 | * value larger than or equal to 3, mark that chunk for |
1da177e4 LT |
1731 | * retransmission and start the fast retransmit procedure. |
1732 | */ | |
1733 | ||
27852c26 | 1734 | if (chunk->tsn_missing_report >= 3) { |
c226ef9b | 1735 | chunk->fast_retransmit = SCTP_NEED_FRTX; |
1da177e4 LT |
1736 | do_fast_retransmit = 1; |
1737 | } | |
1738 | } | |
1739 | ||
1740 | if (transport) { | |
1741 | if (do_fast_retransmit) | |
1742 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1743 | ||
1744 | SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, " | |
1745 | "ssthresh: %d, flight_size: %d, pba: %d\n", | |
0dc47877 | 1746 | __func__, transport, transport->cwnd, |
d808ad9a | 1747 | transport->ssthresh, transport->flight_size, |
1da177e4 LT |
1748 | transport->partial_bytes_acked); |
1749 | } | |
1750 | } | |
1751 | ||
1752 | /* Is the given TSN acked by this packet? */ | |
1753 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1754 | { | |
1755 | int i; | |
1756 | sctp_sack_variable_t *frags; | |
1757 | __u16 gap; | |
1758 | __u32 ctsn = ntohl(sack->cum_tsn_ack); | |
1759 | ||
d808ad9a | 1760 | if (TSN_lte(tsn, ctsn)) |
1da177e4 LT |
1761 | goto pass; |
1762 | ||
1763 | /* 3.3.4 Selective Acknowledgement (SACK) (3): | |
1764 | * | |
1765 | * Gap Ack Blocks: | |
1766 | * These fields contain the Gap Ack Blocks. They are repeated | |
1767 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1768 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1769 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1770 | * Ack + Gap Ack Block Start) and less than or equal to | |
1771 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1772 | * Block are assumed to have been received correctly. | |
1773 | */ | |
1774 | ||
1775 | frags = sack->variable; | |
1776 | gap = tsn - ctsn; | |
1777 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { | |
1778 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && | |
1779 | TSN_lte(gap, ntohs(frags[i].gab.end))) | |
1780 | goto pass; | |
1781 | } | |
1782 | ||
1783 | return 0; | |
1784 | pass: | |
1785 | return 1; | |
1786 | } | |
1787 | ||
1788 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
9f81bcd9 | 1789 | int nskips, __be16 stream) |
1da177e4 LT |
1790 | { |
1791 | int i; | |
1792 | ||
1793 | for (i = 0; i < nskips; i++) { | |
1794 | if (skiplist[i].stream == stream) | |
1795 | return i; | |
1796 | } | |
1797 | return i; | |
1798 | } | |
1799 | ||
1800 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
1801 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) | |
1802 | { | |
1803 | struct sctp_association *asoc = q->asoc; | |
1804 | struct sctp_chunk *ftsn_chunk = NULL; | |
1805 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1806 | int nskips = 0; | |
1807 | int skip_pos = 0; | |
1808 | __u32 tsn; | |
1809 | struct sctp_chunk *chunk; | |
1810 | struct list_head *lchunk, *temp; | |
1811 | ||
76595024 WY |
1812 | if (!asoc->peer.prsctp_capable) |
1813 | return; | |
1814 | ||
1da177e4 LT |
1815 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
1816 | * received SACK. | |
d808ad9a | 1817 | * |
1da177e4 LT |
1818 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
1819 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1820 | */ | |
1821 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1822 | asoc->adv_peer_ack_point = ctsn; | |
1823 | ||
1824 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1825 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1826 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1827 | * shown in the following example: | |
1828 | * | |
1829 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1830 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
d808ad9a | 1831 | * |
1da177e4 LT |
1832 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
1833 | * normal SACK processing local advancement | |
1834 | * ... ... | |
1835 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1836 | * 103 abandoned 103 abandoned | |
1837 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1838 | * 105 105 | |
1839 | * 106 acked 106 acked | |
1840 | * ... ... | |
1841 | * | |
1842 | * In this example, the data sender successfully advanced the | |
1843 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1844 | */ | |
1845 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1846 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1847 | transmitted_list); | |
1848 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1849 | ||
1850 | /* Remove any chunks in the abandoned queue that are acked by | |
1851 | * the ctsn. | |
d808ad9a | 1852 | */ |
1da177e4 LT |
1853 | if (TSN_lte(tsn, ctsn)) { |
1854 | list_del_init(lchunk); | |
1da177e4 LT |
1855 | sctp_chunk_free(chunk); |
1856 | } else { | |
1857 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1858 | asoc->adv_peer_ack_point = tsn; | |
1859 | if (chunk->chunk_hdr->flags & | |
1860 | SCTP_DATA_UNORDERED) | |
1861 | continue; | |
1862 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1863 | nskips, | |
1864 | chunk->subh.data_hdr->stream); | |
1865 | ftsn_skip_arr[skip_pos].stream = | |
1866 | chunk->subh.data_hdr->stream; | |
1867 | ftsn_skip_arr[skip_pos].ssn = | |
1868 | chunk->subh.data_hdr->ssn; | |
1869 | if (skip_pos == nskips) | |
1870 | nskips++; | |
1871 | if (nskips == 10) | |
1872 | break; | |
1873 | } else | |
1874 | break; | |
1875 | } | |
1876 | } | |
1877 | ||
1878 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1879 | * is greater than the Cumulative TSN ACK carried in the received | |
1880 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1881 | * chunk containing the latest value of the | |
1882 | * "Advanced.Peer.Ack.Point". | |
1883 | * | |
1884 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1885 | * list each stream and sequence number in the forwarded TSN. This | |
1886 | * information will enable the receiver to easily find any | |
1887 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1888 | * SHOULD only be reported once; this means that if multiple | |
1889 | * abandoned messages occur in the same stream then only the | |
1890 | * highest abandoned stream sequence number is reported. If the | |
1891 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1892 | * the sender of the FORWARD TSN SHOULD lower the | |
1893 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1894 | * single MTU. | |
1895 | */ | |
1896 | if (asoc->adv_peer_ack_point > ctsn) | |
1897 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
d808ad9a | 1898 | nskips, &ftsn_skip_arr[0]); |
1da177e4 LT |
1899 | |
1900 | if (ftsn_chunk) { | |
79af02c2 | 1901 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
1da177e4 LT |
1902 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
1903 | } | |
1904 | } |