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1da177e4 LT |
1 | /* SCTP kernel reference Implementation |
2 | * (C) Copyright IBM Corp. 2001, 2004 | |
3 | * Copyright (c) 1999-2000 Cisco, Inc. | |
4 | * Copyright (c) 1999-2001 Motorola, Inc. | |
5 | * Copyright (c) 2001-2003 Intel Corp. | |
6 | * | |
7 | * This file is part of the SCTP kernel reference Implementation | |
8 | * | |
9 | * These functions implement the sctp_outq class. The outqueue handles | |
10 | * bundling and queueing of outgoing SCTP chunks. | |
11 | * | |
12 | * The SCTP reference implementation is free software; | |
13 | * you can redistribute it and/or modify it under the terms of | |
14 | * the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2, or (at your option) | |
16 | * any later version. | |
17 | * | |
18 | * The SCTP reference implementation is distributed in the hope that it | |
19 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied | |
20 | * ************************ | |
21 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
22 | * See the GNU General Public License for more details. | |
23 | * | |
24 | * You should have received a copy of the GNU General Public License | |
25 | * along with GNU CC; see the file COPYING. If not, write to | |
26 | * the Free Software Foundation, 59 Temple Place - Suite 330, | |
27 | * Boston, MA 02111-1307, USA. | |
28 | * | |
29 | * Please send any bug reports or fixes you make to the | |
30 | * email address(es): | |
31 | * lksctp developers <lksctp-developers@lists.sourceforge.net> | |
32 | * | |
33 | * Or submit a bug report through the following website: | |
34 | * http://www.sf.net/projects/lksctp | |
35 | * | |
36 | * Written or modified by: | |
37 | * La Monte H.P. Yarroll <piggy@acm.org> | |
38 | * Karl Knutson <karl@athena.chicago.il.us> | |
39 | * Perry Melange <pmelange@null.cc.uic.edu> | |
40 | * Xingang Guo <xingang.guo@intel.com> | |
41 | * Hui Huang <hui.huang@nokia.com> | |
42 | * Sridhar Samudrala <sri@us.ibm.com> | |
43 | * Jon Grimm <jgrimm@us.ibm.com> | |
44 | * | |
45 | * Any bugs reported given to us we will try to fix... any fixes shared will | |
46 | * be incorporated into the next SCTP release. | |
47 | */ | |
48 | ||
49 | #include <linux/types.h> | |
50 | #include <linux/list.h> /* For struct list_head */ | |
51 | #include <linux/socket.h> | |
52 | #include <linux/ip.h> | |
53 | #include <net/sock.h> /* For skb_set_owner_w */ | |
54 | ||
55 | #include <net/sctp/sctp.h> | |
56 | #include <net/sctp/sm.h> | |
57 | ||
58 | /* Declare internal functions here. */ | |
59 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); | |
60 | static void sctp_check_transmitted(struct sctp_outq *q, | |
61 | struct list_head *transmitted_queue, | |
62 | struct sctp_transport *transport, | |
63 | struct sctp_sackhdr *sack, | |
64 | __u32 highest_new_tsn); | |
65 | ||
66 | static void sctp_mark_missing(struct sctp_outq *q, | |
67 | struct list_head *transmitted_queue, | |
68 | struct sctp_transport *transport, | |
69 | __u32 highest_new_tsn, | |
70 | int count_of_newacks); | |
71 | ||
72 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); | |
73 | ||
74 | /* Add data to the front of the queue. */ | |
75 | static inline void sctp_outq_head_data(struct sctp_outq *q, | |
76 | struct sctp_chunk *ch) | |
77 | { | |
79af02c2 | 78 | list_add(&ch->list, &q->out_chunk_list); |
1da177e4 LT |
79 | q->out_qlen += ch->skb->len; |
80 | return; | |
81 | } | |
82 | ||
83 | /* Take data from the front of the queue. */ | |
84 | static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) | |
85 | { | |
79af02c2 DM |
86 | struct sctp_chunk *ch = NULL; |
87 | ||
88 | if (!list_empty(&q->out_chunk_list)) { | |
89 | struct list_head *entry = q->out_chunk_list.next; | |
90 | ||
91 | ch = list_entry(entry, struct sctp_chunk, list); | |
92 | list_del_init(entry); | |
1da177e4 | 93 | q->out_qlen -= ch->skb->len; |
79af02c2 | 94 | } |
1da177e4 LT |
95 | return ch; |
96 | } | |
97 | /* Add data chunk to the end of the queue. */ | |
98 | static inline void sctp_outq_tail_data(struct sctp_outq *q, | |
99 | struct sctp_chunk *ch) | |
100 | { | |
79af02c2 | 101 | list_add_tail(&ch->list, &q->out_chunk_list); |
1da177e4 LT |
102 | q->out_qlen += ch->skb->len; |
103 | return; | |
104 | } | |
105 | ||
106 | /* | |
107 | * SFR-CACC algorithm: | |
108 | * D) If count_of_newacks is greater than or equal to 2 | |
109 | * and t was not sent to the current primary then the | |
110 | * sender MUST NOT increment missing report count for t. | |
111 | */ | |
112 | static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, | |
113 | struct sctp_transport *transport, | |
114 | int count_of_newacks) | |
115 | { | |
116 | if (count_of_newacks >=2 && transport != primary) | |
117 | return 1; | |
118 | return 0; | |
119 | } | |
120 | ||
121 | /* | |
122 | * SFR-CACC algorithm: | |
123 | * F) If count_of_newacks is less than 2, let d be the | |
124 | * destination to which t was sent. If cacc_saw_newack | |
125 | * is 0 for destination d, then the sender MUST NOT | |
126 | * increment missing report count for t. | |
127 | */ | |
128 | static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, | |
129 | int count_of_newacks) | |
130 | { | |
131 | if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack) | |
132 | return 1; | |
133 | return 0; | |
134 | } | |
135 | ||
136 | /* | |
137 | * SFR-CACC algorithm: | |
138 | * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD | |
139 | * execute steps C, D, F. | |
140 | * | |
141 | * C has been implemented in sctp_outq_sack | |
142 | */ | |
143 | static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, | |
144 | struct sctp_transport *transport, | |
145 | int count_of_newacks) | |
146 | { | |
147 | if (!primary->cacc.cycling_changeover) { | |
148 | if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks)) | |
149 | return 1; | |
150 | if (sctp_cacc_skip_3_1_f(transport, count_of_newacks)) | |
151 | return 1; | |
152 | return 0; | |
153 | } | |
154 | return 0; | |
155 | } | |
156 | ||
157 | /* | |
158 | * SFR-CACC algorithm: | |
159 | * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less | |
160 | * than next_tsn_at_change of the current primary, then | |
161 | * the sender MUST NOT increment missing report count | |
162 | * for t. | |
163 | */ | |
164 | static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) | |
165 | { | |
166 | if (primary->cacc.cycling_changeover && | |
167 | TSN_lt(tsn, primary->cacc.next_tsn_at_change)) | |
168 | return 1; | |
169 | return 0; | |
170 | } | |
171 | ||
172 | /* | |
173 | * SFR-CACC algorithm: | |
174 | * 3) If the missing report count for TSN t is to be | |
175 | * incremented according to [RFC2960] and | |
176 | * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, | |
177 | * then the sender MUST futher execute steps 3.1 and | |
178 | * 3.2 to determine if the missing report count for | |
179 | * TSN t SHOULD NOT be incremented. | |
180 | * | |
181 | * 3.3) If 3.1 and 3.2 do not dictate that the missing | |
182 | * report count for t should not be incremented, then | |
183 | * the sender SOULD increment missing report count for | |
184 | * t (according to [RFC2960] and [SCTP_STEWART_2002]). | |
185 | */ | |
186 | static inline int sctp_cacc_skip(struct sctp_transport *primary, | |
187 | struct sctp_transport *transport, | |
188 | int count_of_newacks, | |
189 | __u32 tsn) | |
190 | { | |
191 | if (primary->cacc.changeover_active && | |
192 | (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) | |
193 | || sctp_cacc_skip_3_2(primary, tsn))) | |
194 | return 1; | |
195 | return 0; | |
196 | } | |
197 | ||
198 | /* Initialize an existing sctp_outq. This does the boring stuff. | |
199 | * You still need to define handlers if you really want to DO | |
200 | * something with this structure... | |
201 | */ | |
202 | void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) | |
203 | { | |
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); | |
210 | ||
211 | q->outstanding_bytes = 0; | |
212 | q->empty = 1; | |
213 | q->cork = 0; | |
214 | ||
215 | q->malloced = 0; | |
216 | q->out_qlen = 0; | |
217 | } | |
218 | ||
219 | /* Free the outqueue structure and any related pending chunks. | |
220 | */ | |
221 | void sctp_outq_teardown(struct sctp_outq *q) | |
222 | { | |
223 | struct sctp_transport *transport; | |
224 | struct list_head *lchunk, *pos, *temp; | |
79af02c2 | 225 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
226 | |
227 | /* Throw away unacknowledged chunks. */ | |
228 | list_for_each(pos, &q->asoc->peer.transport_addr_list) { | |
229 | transport = list_entry(pos, struct sctp_transport, transports); | |
230 | while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) { | |
231 | chunk = list_entry(lchunk, struct sctp_chunk, | |
232 | transmitted_list); | |
233 | /* Mark as part of a failed message. */ | |
234 | sctp_chunk_fail(chunk, q->error); | |
235 | sctp_chunk_free(chunk); | |
236 | } | |
237 | } | |
238 | ||
239 | /* Throw away chunks that have been gap ACKed. */ | |
240 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
241 | list_del_init(lchunk); | |
242 | chunk = list_entry(lchunk, struct sctp_chunk, | |
243 | transmitted_list); | |
244 | sctp_chunk_fail(chunk, q->error); | |
245 | sctp_chunk_free(chunk); | |
246 | } | |
247 | ||
248 | /* Throw away any chunks in the retransmit queue. */ | |
249 | list_for_each_safe(lchunk, temp, &q->retransmit) { | |
250 | list_del_init(lchunk); | |
251 | chunk = list_entry(lchunk, struct sctp_chunk, | |
252 | transmitted_list); | |
253 | sctp_chunk_fail(chunk, q->error); | |
254 | sctp_chunk_free(chunk); | |
255 | } | |
256 | ||
257 | /* Throw away any chunks that are in the abandoned queue. */ | |
258 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
259 | list_del_init(lchunk); | |
260 | chunk = list_entry(lchunk, struct sctp_chunk, | |
261 | transmitted_list); | |
262 | sctp_chunk_fail(chunk, q->error); | |
263 | sctp_chunk_free(chunk); | |
264 | } | |
265 | ||
266 | /* Throw away any leftover data chunks. */ | |
267 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { | |
268 | ||
269 | /* Mark as send failure. */ | |
270 | sctp_chunk_fail(chunk, q->error); | |
271 | sctp_chunk_free(chunk); | |
272 | } | |
273 | ||
274 | q->error = 0; | |
275 | ||
276 | /* Throw away any leftover control chunks. */ | |
79af02c2 DM |
277 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
278 | list_del_init(&chunk->list); | |
1da177e4 | 279 | sctp_chunk_free(chunk); |
79af02c2 | 280 | } |
1da177e4 LT |
281 | } |
282 | ||
283 | /* Free the outqueue structure and any related pending chunks. */ | |
284 | void sctp_outq_free(struct sctp_outq *q) | |
285 | { | |
286 | /* Throw away leftover chunks. */ | |
287 | sctp_outq_teardown(q); | |
288 | ||
289 | /* If we were kmalloc()'d, free the memory. */ | |
290 | if (q->malloced) | |
291 | kfree(q); | |
292 | } | |
293 | ||
294 | /* Put a new chunk in an sctp_outq. */ | |
295 | int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) | |
296 | { | |
297 | int error = 0; | |
298 | ||
299 | SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n", | |
300 | q, chunk, chunk && chunk->chunk_hdr ? | |
301 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) | |
302 | : "Illegal Chunk"); | |
303 | ||
304 | /* If it is data, queue it up, otherwise, send it | |
305 | * immediately. | |
306 | */ | |
307 | if (SCTP_CID_DATA == chunk->chunk_hdr->type) { | |
308 | /* Is it OK to queue data chunks? */ | |
309 | /* From 9. Termination of Association | |
310 | * | |
311 | * When either endpoint performs a shutdown, the | |
312 | * association on each peer will stop accepting new | |
313 | * data from its user and only deliver data in queue | |
314 | * at the time of sending or receiving the SHUTDOWN | |
315 | * chunk. | |
316 | */ | |
317 | switch (q->asoc->state) { | |
318 | case SCTP_STATE_EMPTY: | |
319 | case SCTP_STATE_CLOSED: | |
320 | case SCTP_STATE_SHUTDOWN_PENDING: | |
321 | case SCTP_STATE_SHUTDOWN_SENT: | |
322 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
323 | case SCTP_STATE_SHUTDOWN_ACK_SENT: | |
324 | /* Cannot send after transport endpoint shutdown */ | |
325 | error = -ESHUTDOWN; | |
326 | break; | |
327 | ||
328 | default: | |
329 | SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n", | |
330 | q, chunk, chunk && chunk->chunk_hdr ? | |
331 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) | |
332 | : "Illegal Chunk"); | |
333 | ||
334 | sctp_outq_tail_data(q, chunk); | |
335 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
336 | SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS); | |
337 | else | |
338 | SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS); | |
339 | q->empty = 0; | |
340 | break; | |
341 | }; | |
342 | } else { | |
79af02c2 | 343 | list_add_tail(&chunk->list, &q->control_chunk_list); |
1da177e4 LT |
344 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
345 | } | |
346 | ||
347 | if (error < 0) | |
348 | return error; | |
349 | ||
350 | if (!q->cork) | |
351 | error = sctp_outq_flush(q, 0); | |
352 | ||
353 | return error; | |
354 | } | |
355 | ||
356 | /* Insert a chunk into the sorted list based on the TSNs. The retransmit list | |
357 | * and the abandoned list are in ascending order. | |
358 | */ | |
359 | static void sctp_insert_list(struct list_head *head, struct list_head *new) | |
360 | { | |
361 | struct list_head *pos; | |
362 | struct sctp_chunk *nchunk, *lchunk; | |
363 | __u32 ntsn, ltsn; | |
364 | int done = 0; | |
365 | ||
366 | nchunk = list_entry(new, struct sctp_chunk, transmitted_list); | |
367 | ntsn = ntohl(nchunk->subh.data_hdr->tsn); | |
368 | ||
369 | list_for_each(pos, head) { | |
370 | lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); | |
371 | ltsn = ntohl(lchunk->subh.data_hdr->tsn); | |
372 | if (TSN_lt(ntsn, ltsn)) { | |
373 | list_add(new, pos->prev); | |
374 | done = 1; | |
375 | break; | |
376 | } | |
377 | } | |
378 | if (!done) | |
379 | list_add_tail(new, head); | |
380 | } | |
381 | ||
382 | /* Mark all the eligible packets on a transport for retransmission. */ | |
383 | void sctp_retransmit_mark(struct sctp_outq *q, | |
384 | struct sctp_transport *transport, | |
385 | __u8 fast_retransmit) | |
386 | { | |
387 | struct list_head *lchunk, *ltemp; | |
388 | struct sctp_chunk *chunk; | |
389 | ||
390 | /* Walk through the specified transmitted queue. */ | |
391 | list_for_each_safe(lchunk, ltemp, &transport->transmitted) { | |
392 | chunk = list_entry(lchunk, struct sctp_chunk, | |
393 | transmitted_list); | |
394 | ||
395 | /* If the chunk is abandoned, move it to abandoned list. */ | |
396 | if (sctp_chunk_abandoned(chunk)) { | |
397 | list_del_init(lchunk); | |
398 | sctp_insert_list(&q->abandoned, lchunk); | |
399 | continue; | |
400 | } | |
401 | ||
402 | /* If we are doing retransmission due to a fast retransmit, | |
403 | * only the chunk's that are marked for fast retransmit | |
404 | * should be added to the retransmit queue. If we are doing | |
405 | * retransmission due to a timeout or pmtu discovery, only the | |
406 | * chunks that are not yet acked should be added to the | |
407 | * retransmit queue. | |
408 | */ | |
409 | if ((fast_retransmit && chunk->fast_retransmit) || | |
410 | (!fast_retransmit && !chunk->tsn_gap_acked)) { | |
411 | /* RFC 2960 6.2.1 Processing a Received SACK | |
412 | * | |
413 | * C) Any time a DATA chunk is marked for | |
414 | * retransmission (via either T3-rtx timer expiration | |
415 | * (Section 6.3.3) or via fast retransmit | |
416 | * (Section 7.2.4)), add the data size of those | |
417 | * chunks to the rwnd. | |
418 | */ | |
419 | q->asoc->peer.rwnd += sctp_data_size(chunk); | |
420 | q->outstanding_bytes -= sctp_data_size(chunk); | |
421 | transport->flight_size -= sctp_data_size(chunk); | |
422 | ||
423 | /* sctpimpguide-05 Section 2.8.2 | |
424 | * M5) If a T3-rtx timer expires, the | |
425 | * 'TSN.Missing.Report' of all affected TSNs is set | |
426 | * to 0. | |
427 | */ | |
428 | chunk->tsn_missing_report = 0; | |
429 | ||
430 | /* If a chunk that is being used for RTT measurement | |
431 | * has to be retransmitted, we cannot use this chunk | |
432 | * anymore for RTT measurements. Reset rto_pending so | |
433 | * that a new RTT measurement is started when a new | |
434 | * data chunk is sent. | |
435 | */ | |
436 | if (chunk->rtt_in_progress) { | |
437 | chunk->rtt_in_progress = 0; | |
438 | transport->rto_pending = 0; | |
439 | } | |
440 | ||
441 | /* Move the chunk to the retransmit queue. The chunks | |
442 | * on the retransmit queue are always kept in order. | |
443 | */ | |
444 | list_del_init(lchunk); | |
445 | sctp_insert_list(&q->retransmit, lchunk); | |
446 | } | |
447 | } | |
448 | ||
449 | SCTP_DEBUG_PRINTK("%s: transport: %p, fast_retransmit: %d, " | |
450 | "cwnd: %d, ssthresh: %d, flight_size: %d, " | |
451 | "pba: %d\n", __FUNCTION__, | |
452 | transport, fast_retransmit, | |
453 | transport->cwnd, transport->ssthresh, | |
454 | transport->flight_size, | |
455 | transport->partial_bytes_acked); | |
456 | ||
457 | } | |
458 | ||
459 | /* Mark all the eligible packets on a transport for retransmission and force | |
460 | * one packet out. | |
461 | */ | |
462 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, | |
463 | sctp_retransmit_reason_t reason) | |
464 | { | |
465 | int error = 0; | |
466 | __u8 fast_retransmit = 0; | |
467 | ||
468 | switch(reason) { | |
469 | case SCTP_RTXR_T3_RTX: | |
470 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); | |
471 | /* Update the retran path if the T3-rtx timer has expired for | |
472 | * the current retran path. | |
473 | */ | |
474 | if (transport == transport->asoc->peer.retran_path) | |
475 | sctp_assoc_update_retran_path(transport->asoc); | |
476 | break; | |
477 | case SCTP_RTXR_FAST_RTX: | |
478 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); | |
479 | fast_retransmit = 1; | |
480 | break; | |
481 | case SCTP_RTXR_PMTUD: | |
482 | default: | |
483 | break; | |
484 | } | |
485 | ||
486 | sctp_retransmit_mark(q, transport, fast_retransmit); | |
487 | ||
488 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, | |
489 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by | |
490 | * following the procedures outlined in C1 - C5. | |
491 | */ | |
492 | sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); | |
493 | ||
494 | error = sctp_outq_flush(q, /* rtx_timeout */ 1); | |
495 | ||
496 | if (error) | |
497 | q->asoc->base.sk->sk_err = -error; | |
498 | } | |
499 | ||
500 | /* | |
501 | * Transmit DATA chunks on the retransmit queue. Upon return from | |
502 | * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which | |
503 | * need to be transmitted by the caller. | |
504 | * We assume that pkt->transport has already been set. | |
505 | * | |
506 | * The return value is a normal kernel error return value. | |
507 | */ | |
508 | static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, | |
509 | int rtx_timeout, int *start_timer) | |
510 | { | |
511 | struct list_head *lqueue; | |
512 | struct list_head *lchunk, *lchunk1; | |
513 | struct sctp_transport *transport = pkt->transport; | |
514 | sctp_xmit_t status; | |
515 | struct sctp_chunk *chunk, *chunk1; | |
516 | struct sctp_association *asoc; | |
517 | int error = 0; | |
518 | ||
519 | asoc = q->asoc; | |
520 | lqueue = &q->retransmit; | |
521 | ||
522 | /* RFC 2960 6.3.3 Handle T3-rtx Expiration | |
523 | * | |
524 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
525 | * outstanding DATA chunks for the address for which the | |
526 | * T3-rtx has expired will fit into a single packet, subject | |
527 | * to the MTU constraint for the path corresponding to the | |
528 | * destination transport address to which the retransmission | |
529 | * is being sent (this may be different from the address for | |
530 | * which the timer expires [see Section 6.4]). Call this value | |
531 | * K. Bundle and retransmit those K DATA chunks in a single | |
532 | * packet to the destination endpoint. | |
533 | * | |
534 | * [Just to be painfully clear, if we are retransmitting | |
535 | * because a timeout just happened, we should send only ONE | |
536 | * packet of retransmitted data.] | |
537 | */ | |
538 | lchunk = sctp_list_dequeue(lqueue); | |
539 | ||
540 | while (lchunk) { | |
541 | chunk = list_entry(lchunk, struct sctp_chunk, | |
542 | transmitted_list); | |
543 | ||
544 | /* Make sure that Gap Acked TSNs are not retransmitted. A | |
545 | * simple approach is just to move such TSNs out of the | |
546 | * way and into a 'transmitted' queue and skip to the | |
547 | * next chunk. | |
548 | */ | |
549 | if (chunk->tsn_gap_acked) { | |
550 | list_add_tail(lchunk, &transport->transmitted); | |
551 | lchunk = sctp_list_dequeue(lqueue); | |
552 | continue; | |
553 | } | |
554 | ||
555 | /* Attempt to append this chunk to the packet. */ | |
556 | status = sctp_packet_append_chunk(pkt, chunk); | |
557 | ||
558 | switch (status) { | |
559 | case SCTP_XMIT_PMTU_FULL: | |
560 | /* Send this packet. */ | |
561 | if ((error = sctp_packet_transmit(pkt)) == 0) | |
562 | *start_timer = 1; | |
563 | ||
564 | /* If we are retransmitting, we should only | |
565 | * send a single packet. | |
566 | */ | |
567 | if (rtx_timeout) { | |
568 | list_add(lchunk, lqueue); | |
569 | lchunk = NULL; | |
570 | } | |
571 | ||
572 | /* Bundle lchunk in the next round. */ | |
573 | break; | |
574 | ||
575 | case SCTP_XMIT_RWND_FULL: | |
576 | /* Send this packet. */ | |
577 | if ((error = sctp_packet_transmit(pkt)) == 0) | |
578 | *start_timer = 1; | |
579 | ||
580 | /* Stop sending DATA as there is no more room | |
581 | * at the receiver. | |
582 | */ | |
583 | list_add(lchunk, lqueue); | |
584 | lchunk = NULL; | |
585 | break; | |
586 | ||
587 | case SCTP_XMIT_NAGLE_DELAY: | |
588 | /* Send this packet. */ | |
589 | if ((error = sctp_packet_transmit(pkt)) == 0) | |
590 | *start_timer = 1; | |
591 | ||
592 | /* Stop sending DATA because of nagle delay. */ | |
593 | list_add(lchunk, lqueue); | |
594 | lchunk = NULL; | |
595 | break; | |
596 | ||
597 | default: | |
598 | /* The append was successful, so add this chunk to | |
599 | * the transmitted list. | |
600 | */ | |
601 | list_add_tail(lchunk, &transport->transmitted); | |
602 | ||
603 | /* Mark the chunk as ineligible for fast retransmit | |
604 | * after it is retransmitted. | |
605 | */ | |
606 | chunk->fast_retransmit = 0; | |
607 | ||
608 | *start_timer = 1; | |
609 | q->empty = 0; | |
610 | ||
611 | /* Retrieve a new chunk to bundle. */ | |
612 | lchunk = sctp_list_dequeue(lqueue); | |
613 | break; | |
614 | }; | |
615 | ||
616 | /* If we are here due to a retransmit timeout or a fast | |
617 | * retransmit and if there are any chunks left in the retransmit | |
618 | * queue that could not fit in the PMTU sized packet, they need * to be marked as ineligible for a subsequent fast retransmit. | |
619 | */ | |
620 | if (rtx_timeout && !lchunk) { | |
621 | list_for_each(lchunk1, lqueue) { | |
622 | chunk1 = list_entry(lchunk1, struct sctp_chunk, | |
623 | transmitted_list); | |
624 | chunk1->fast_retransmit = 0; | |
625 | } | |
626 | } | |
627 | } | |
628 | ||
629 | return error; | |
630 | } | |
631 | ||
632 | /* Cork the outqueue so queued chunks are really queued. */ | |
633 | int sctp_outq_uncork(struct sctp_outq *q) | |
634 | { | |
635 | int error = 0; | |
636 | if (q->cork) { | |
637 | q->cork = 0; | |
638 | error = sctp_outq_flush(q, 0); | |
639 | } | |
640 | return error; | |
641 | } | |
642 | ||
643 | /* | |
644 | * Try to flush an outqueue. | |
645 | * | |
646 | * Description: Send everything in q which we legally can, subject to | |
647 | * congestion limitations. | |
648 | * * Note: This function can be called from multiple contexts so appropriate | |
649 | * locking concerns must be made. Today we use the sock lock to protect | |
650 | * this function. | |
651 | */ | |
652 | int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) | |
653 | { | |
654 | struct sctp_packet *packet; | |
655 | struct sctp_packet singleton; | |
656 | struct sctp_association *asoc = q->asoc; | |
657 | __u16 sport = asoc->base.bind_addr.port; | |
658 | __u16 dport = asoc->peer.port; | |
659 | __u32 vtag = asoc->peer.i.init_tag; | |
1da177e4 LT |
660 | struct sctp_transport *transport = NULL; |
661 | struct sctp_transport *new_transport; | |
79af02c2 | 662 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
663 | sctp_xmit_t status; |
664 | int error = 0; | |
665 | int start_timer = 0; | |
666 | ||
667 | /* These transports have chunks to send. */ | |
668 | struct list_head transport_list; | |
669 | struct list_head *ltransport; | |
670 | ||
671 | INIT_LIST_HEAD(&transport_list); | |
672 | packet = NULL; | |
673 | ||
674 | /* | |
675 | * 6.10 Bundling | |
676 | * ... | |
677 | * When bundling control chunks with DATA chunks, an | |
678 | * endpoint MUST place control chunks first in the outbound | |
679 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
680 | * within a SCTP packet in increasing order of TSN. | |
681 | * ... | |
682 | */ | |
683 | ||
79af02c2 DM |
684 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
685 | list_del_init(&chunk->list); | |
686 | ||
1da177e4 LT |
687 | /* Pick the right transport to use. */ |
688 | new_transport = chunk->transport; | |
689 | ||
690 | if (!new_transport) { | |
691 | new_transport = asoc->peer.active_path; | |
3f7a87d2 FF |
692 | } else if (new_transport->state == SCTP_INACTIVE) { |
693 | /* If the chunk is Heartbeat or Heartbeat Ack, | |
694 | * send it to chunk->transport, even if it's | |
1da177e4 LT |
695 | * inactive. |
696 | * | |
697 | * 3.3.6 Heartbeat Acknowledgement: | |
698 | * ... | |
699 | * A HEARTBEAT ACK is always sent to the source IP | |
700 | * address of the IP datagram containing the | |
701 | * HEARTBEAT chunk to which this ack is responding. | |
702 | * ... | |
703 | */ | |
704 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && | |
705 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK) | |
706 | new_transport = asoc->peer.active_path; | |
707 | } | |
708 | ||
709 | /* Are we switching transports? | |
710 | * Take care of transport locks. | |
711 | */ | |
712 | if (new_transport != transport) { | |
713 | transport = new_transport; | |
714 | if (list_empty(&transport->send_ready)) { | |
715 | list_add_tail(&transport->send_ready, | |
716 | &transport_list); | |
717 | } | |
718 | packet = &transport->packet; | |
719 | sctp_packet_config(packet, vtag, | |
720 | asoc->peer.ecn_capable); | |
721 | } | |
722 | ||
723 | switch (chunk->chunk_hdr->type) { | |
724 | /* | |
725 | * 6.10 Bundling | |
726 | * ... | |
727 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
728 | * COMPLETE with any other chunks. [Send them immediately.] | |
729 | */ | |
730 | case SCTP_CID_INIT: | |
731 | case SCTP_CID_INIT_ACK: | |
732 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
733 | sctp_packet_init(&singleton, transport, sport, dport); | |
734 | sctp_packet_config(&singleton, vtag, 0); | |
735 | sctp_packet_append_chunk(&singleton, chunk); | |
736 | error = sctp_packet_transmit(&singleton); | |
737 | if (error < 0) | |
738 | return error; | |
739 | break; | |
740 | ||
741 | case SCTP_CID_ABORT: | |
742 | case SCTP_CID_SACK: | |
743 | case SCTP_CID_HEARTBEAT: | |
744 | case SCTP_CID_HEARTBEAT_ACK: | |
745 | case SCTP_CID_SHUTDOWN: | |
746 | case SCTP_CID_SHUTDOWN_ACK: | |
747 | case SCTP_CID_ERROR: | |
748 | case SCTP_CID_COOKIE_ECHO: | |
749 | case SCTP_CID_COOKIE_ACK: | |
750 | case SCTP_CID_ECN_ECNE: | |
751 | case SCTP_CID_ECN_CWR: | |
752 | case SCTP_CID_ASCONF: | |
753 | case SCTP_CID_ASCONF_ACK: | |
754 | case SCTP_CID_FWD_TSN: | |
755 | sctp_packet_transmit_chunk(packet, chunk); | |
756 | break; | |
757 | ||
758 | default: | |
759 | /* We built a chunk with an illegal type! */ | |
760 | BUG(); | |
761 | }; | |
762 | } | |
763 | ||
764 | /* Is it OK to send data chunks? */ | |
765 | switch (asoc->state) { | |
766 | case SCTP_STATE_COOKIE_ECHOED: | |
767 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
768 | * chunk. | |
769 | */ | |
770 | if (!packet || !packet->has_cookie_echo) | |
771 | break; | |
772 | ||
773 | /* fallthru */ | |
774 | case SCTP_STATE_ESTABLISHED: | |
775 | case SCTP_STATE_SHUTDOWN_PENDING: | |
776 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
777 | /* | |
778 | * RFC 2960 6.1 Transmission of DATA Chunks | |
779 | * | |
780 | * C) When the time comes for the sender to transmit, | |
781 | * before sending new DATA chunks, the sender MUST | |
782 | * first transmit any outstanding DATA chunks which | |
783 | * are marked for retransmission (limited by the | |
784 | * current cwnd). | |
785 | */ | |
786 | if (!list_empty(&q->retransmit)) { | |
787 | if (transport == asoc->peer.retran_path) | |
788 | goto retran; | |
789 | ||
790 | /* Switch transports & prepare the packet. */ | |
791 | ||
792 | transport = asoc->peer.retran_path; | |
793 | ||
794 | if (list_empty(&transport->send_ready)) { | |
795 | list_add_tail(&transport->send_ready, | |
796 | &transport_list); | |
797 | } | |
798 | ||
799 | packet = &transport->packet; | |
800 | sctp_packet_config(packet, vtag, | |
801 | asoc->peer.ecn_capable); | |
802 | retran: | |
803 | error = sctp_outq_flush_rtx(q, packet, | |
804 | rtx_timeout, &start_timer); | |
805 | ||
806 | if (start_timer) | |
807 | sctp_transport_reset_timers(transport); | |
808 | ||
809 | /* This can happen on COOKIE-ECHO resend. Only | |
810 | * one chunk can get bundled with a COOKIE-ECHO. | |
811 | */ | |
812 | if (packet->has_cookie_echo) | |
813 | goto sctp_flush_out; | |
814 | ||
815 | /* Don't send new data if there is still data | |
816 | * waiting to retransmit. | |
817 | */ | |
818 | if (!list_empty(&q->retransmit)) | |
819 | goto sctp_flush_out; | |
820 | } | |
821 | ||
822 | /* Finally, transmit new packets. */ | |
823 | start_timer = 0; | |
1da177e4 LT |
824 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
825 | /* RFC 2960 6.5 Every DATA chunk MUST carry a valid | |
826 | * stream identifier. | |
827 | */ | |
828 | if (chunk->sinfo.sinfo_stream >= | |
829 | asoc->c.sinit_num_ostreams) { | |
830 | ||
831 | /* Mark as failed send. */ | |
832 | sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); | |
833 | sctp_chunk_free(chunk); | |
834 | continue; | |
835 | } | |
836 | ||
837 | /* Has this chunk expired? */ | |
838 | if (sctp_chunk_abandoned(chunk)) { | |
839 | sctp_chunk_fail(chunk, 0); | |
840 | sctp_chunk_free(chunk); | |
841 | continue; | |
842 | } | |
843 | ||
844 | /* If there is a specified transport, use it. | |
845 | * Otherwise, we want to use the active path. | |
846 | */ | |
847 | new_transport = chunk->transport; | |
3f7a87d2 FF |
848 | if (!new_transport || |
849 | new_transport->state == SCTP_INACTIVE) | |
1da177e4 LT |
850 | new_transport = asoc->peer.active_path; |
851 | ||
852 | /* Change packets if necessary. */ | |
853 | if (new_transport != transport) { | |
854 | transport = new_transport; | |
855 | ||
856 | /* Schedule to have this transport's | |
857 | * packet flushed. | |
858 | */ | |
859 | if (list_empty(&transport->send_ready)) { | |
860 | list_add_tail(&transport->send_ready, | |
861 | &transport_list); | |
862 | } | |
863 | ||
864 | packet = &transport->packet; | |
865 | sctp_packet_config(packet, vtag, | |
866 | asoc->peer.ecn_capable); | |
867 | } | |
868 | ||
869 | SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ", | |
870 | q, chunk, | |
871 | chunk && chunk->chunk_hdr ? | |
872 | sctp_cname(SCTP_ST_CHUNK( | |
873 | chunk->chunk_hdr->type)) | |
874 | : "Illegal Chunk"); | |
875 | ||
876 | SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head " | |
877 | "%p skb->users %d.\n", | |
878 | ntohl(chunk->subh.data_hdr->tsn), | |
879 | chunk->skb ?chunk->skb->head : NULL, | |
880 | chunk->skb ? | |
881 | atomic_read(&chunk->skb->users) : -1); | |
882 | ||
883 | /* Add the chunk to the packet. */ | |
884 | status = sctp_packet_transmit_chunk(packet, chunk); | |
885 | ||
886 | switch (status) { | |
887 | case SCTP_XMIT_PMTU_FULL: | |
888 | case SCTP_XMIT_RWND_FULL: | |
889 | case SCTP_XMIT_NAGLE_DELAY: | |
890 | /* We could not append this chunk, so put | |
891 | * the chunk back on the output queue. | |
892 | */ | |
893 | SCTP_DEBUG_PRINTK("sctp_outq_flush: could " | |
894 | "not transmit TSN: 0x%x, status: %d\n", | |
895 | ntohl(chunk->subh.data_hdr->tsn), | |
896 | status); | |
897 | sctp_outq_head_data(q, chunk); | |
898 | goto sctp_flush_out; | |
899 | break; | |
900 | ||
901 | case SCTP_XMIT_OK: | |
902 | break; | |
903 | ||
904 | default: | |
905 | BUG(); | |
906 | } | |
907 | ||
908 | /* BUG: We assume that the sctp_packet_transmit() | |
909 | * call below will succeed all the time and add the | |
910 | * chunk to the transmitted list and restart the | |
911 | * timers. | |
912 | * It is possible that the call can fail under OOM | |
913 | * conditions. | |
914 | * | |
915 | * Is this really a problem? Won't this behave | |
916 | * like a lost TSN? | |
917 | */ | |
918 | list_add_tail(&chunk->transmitted_list, | |
919 | &transport->transmitted); | |
920 | ||
921 | sctp_transport_reset_timers(transport); | |
922 | ||
923 | q->empty = 0; | |
924 | ||
925 | /* Only let one DATA chunk get bundled with a | |
926 | * COOKIE-ECHO chunk. | |
927 | */ | |
928 | if (packet->has_cookie_echo) | |
929 | goto sctp_flush_out; | |
930 | } | |
931 | break; | |
932 | ||
933 | default: | |
934 | /* Do nothing. */ | |
935 | break; | |
936 | } | |
937 | ||
938 | sctp_flush_out: | |
939 | ||
940 | /* Before returning, examine all the transports touched in | |
941 | * this call. Right now, we bluntly force clear all the | |
942 | * transports. Things might change after we implement Nagle. | |
943 | * But such an examination is still required. | |
944 | * | |
945 | * --xguo | |
946 | */ | |
947 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) { | |
948 | struct sctp_transport *t = list_entry(ltransport, | |
949 | struct sctp_transport, | |
950 | send_ready); | |
951 | packet = &t->packet; | |
952 | if (!sctp_packet_empty(packet)) | |
953 | error = sctp_packet_transmit(packet); | |
954 | } | |
955 | ||
956 | return error; | |
957 | } | |
958 | ||
959 | /* Update unack_data based on the incoming SACK chunk */ | |
960 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
961 | struct sctp_sackhdr *sack) | |
962 | { | |
963 | sctp_sack_variable_t *frags; | |
964 | __u16 unack_data; | |
965 | int i; | |
966 | ||
967 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
968 | ||
969 | frags = sack->variable; | |
970 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
971 | unack_data -= ((ntohs(frags[i].gab.end) - | |
972 | ntohs(frags[i].gab.start) + 1)); | |
973 | } | |
974 | ||
975 | assoc->unack_data = unack_data; | |
976 | } | |
977 | ||
978 | /* Return the highest new tsn that is acknowledged by the given SACK chunk. */ | |
979 | static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack, | |
980 | struct sctp_association *asoc) | |
981 | { | |
982 | struct list_head *ltransport, *lchunk; | |
983 | struct sctp_transport *transport; | |
984 | struct sctp_chunk *chunk; | |
985 | __u32 highest_new_tsn, tsn; | |
986 | struct list_head *transport_list = &asoc->peer.transport_addr_list; | |
987 | ||
988 | highest_new_tsn = ntohl(sack->cum_tsn_ack); | |
989 | ||
990 | list_for_each(ltransport, transport_list) { | |
991 | transport = list_entry(ltransport, struct sctp_transport, | |
992 | transports); | |
993 | list_for_each(lchunk, &transport->transmitted) { | |
994 | chunk = list_entry(lchunk, struct sctp_chunk, | |
995 | transmitted_list); | |
996 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
997 | ||
998 | if (!chunk->tsn_gap_acked && | |
999 | TSN_lt(highest_new_tsn, tsn) && | |
1000 | sctp_acked(sack, tsn)) | |
1001 | highest_new_tsn = tsn; | |
1002 | } | |
1003 | } | |
1004 | ||
1005 | return highest_new_tsn; | |
1006 | } | |
1007 | ||
1008 | /* This is where we REALLY process a SACK. | |
1009 | * | |
1010 | * Process the SACK against the outqueue. Mostly, this just frees | |
1011 | * things off the transmitted queue. | |
1012 | */ | |
1013 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) | |
1014 | { | |
1015 | struct sctp_association *asoc = q->asoc; | |
1016 | struct sctp_transport *transport; | |
1017 | struct sctp_chunk *tchunk = NULL; | |
1018 | struct list_head *lchunk, *transport_list, *pos, *temp; | |
1019 | sctp_sack_variable_t *frags = sack->variable; | |
1020 | __u32 sack_ctsn, ctsn, tsn; | |
1021 | __u32 highest_tsn, highest_new_tsn; | |
1022 | __u32 sack_a_rwnd; | |
1023 | unsigned outstanding; | |
1024 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1025 | int count_of_newacks = 0; | |
1026 | ||
1027 | /* Grab the association's destination address list. */ | |
1028 | transport_list = &asoc->peer.transport_addr_list; | |
1029 | ||
1030 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
1031 | ||
1032 | /* | |
1033 | * SFR-CACC algorithm: | |
1034 | * On receipt of a SACK the sender SHOULD execute the | |
1035 | * following statements. | |
1036 | * | |
1037 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1038 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1039 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1040 | * all destinations. | |
1041 | */ | |
1042 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1043 | primary->cacc.changeover_active = 0; | |
1044 | list_for_each(pos, transport_list) { | |
1045 | transport = list_entry(pos, struct sctp_transport, | |
1046 | transports); | |
1047 | transport->cacc.cycling_changeover = 0; | |
1048 | } | |
1049 | } | |
1050 | ||
1051 | /* | |
1052 | * SFR-CACC algorithm: | |
1053 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE | |
1054 | * is set the receiver of the SACK MUST take the following actions: | |
1055 | * | |
1056 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1057 | * addresses. | |
1058 | */ | |
1059 | if (sack->num_gap_ack_blocks > 0 && | |
1060 | primary->cacc.changeover_active) { | |
1061 | list_for_each(pos, transport_list) { | |
1062 | transport = list_entry(pos, struct sctp_transport, | |
1063 | transports); | |
1064 | transport->cacc.cacc_saw_newack = 0; | |
1065 | } | |
1066 | } | |
1067 | ||
1068 | /* Get the highest TSN in the sack. */ | |
1069 | highest_tsn = sack_ctsn; | |
1070 | if (sack->num_gap_ack_blocks) | |
1071 | highest_tsn += | |
1072 | ntohs(frags[ntohs(sack->num_gap_ack_blocks) - 1].gab.end); | |
1073 | ||
1074 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) { | |
1075 | highest_new_tsn = highest_tsn; | |
1076 | asoc->highest_sacked = highest_tsn; | |
1077 | } else { | |
1078 | highest_new_tsn = sctp_highest_new_tsn(sack, asoc); | |
1079 | } | |
1080 | ||
1081 | /* Run through the retransmit queue. Credit bytes received | |
1082 | * and free those chunks that we can. | |
1083 | */ | |
1084 | sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn); | |
1085 | sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0); | |
1086 | ||
1087 | /* Run through the transmitted queue. | |
1088 | * Credit bytes received and free those chunks which we can. | |
1089 | * | |
1090 | * This is a MASSIVE candidate for optimization. | |
1091 | */ | |
1092 | list_for_each(pos, transport_list) { | |
1093 | transport = list_entry(pos, struct sctp_transport, | |
1094 | transports); | |
1095 | sctp_check_transmitted(q, &transport->transmitted, | |
1096 | transport, sack, highest_new_tsn); | |
1097 | /* | |
1098 | * SFR-CACC algorithm: | |
1099 | * C) Let count_of_newacks be the number of | |
1100 | * destinations for which cacc_saw_newack is set. | |
1101 | */ | |
1102 | if (transport->cacc.cacc_saw_newack) | |
1103 | count_of_newacks ++; | |
1104 | } | |
1105 | ||
1106 | list_for_each(pos, transport_list) { | |
1107 | transport = list_entry(pos, struct sctp_transport, | |
1108 | transports); | |
1109 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1110 | highest_new_tsn, count_of_newacks); | |
1111 | } | |
1112 | ||
1113 | /* Move the Cumulative TSN Ack Point if appropriate. */ | |
1114 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) | |
1115 | asoc->ctsn_ack_point = sack_ctsn; | |
1116 | ||
1117 | /* Update unack_data field in the assoc. */ | |
1118 | sctp_sack_update_unack_data(asoc, sack); | |
1119 | ||
1120 | ctsn = asoc->ctsn_ack_point; | |
1121 | ||
1122 | /* Throw away stuff rotting on the sack queue. */ | |
1123 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1124 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1125 | transmitted_list); | |
1126 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1127 | if (TSN_lte(tsn, ctsn)) | |
1128 | sctp_chunk_free(tchunk); | |
1129 | } | |
1130 | ||
1131 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1132 | * number of bytes still outstanding after processing the | |
1133 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1134 | */ | |
1135 | ||
1136 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
1137 | outstanding = q->outstanding_bytes; | |
1138 | ||
1139 | if (outstanding < sack_a_rwnd) | |
1140 | sack_a_rwnd -= outstanding; | |
1141 | else | |
1142 | sack_a_rwnd = 0; | |
1143 | ||
1144 | asoc->peer.rwnd = sack_a_rwnd; | |
1145 | ||
1146 | sctp_generate_fwdtsn(q, sack_ctsn); | |
1147 | ||
1148 | SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n", | |
1149 | __FUNCTION__, sack_ctsn); | |
1150 | SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, " | |
1151 | "%p is 0x%x. Adv peer ack point: 0x%x\n", | |
1152 | __FUNCTION__, asoc, ctsn, asoc->adv_peer_ack_point); | |
1153 | ||
1154 | /* See if all chunks are acked. | |
1155 | * Make sure the empty queue handler will get run later. | |
1156 | */ | |
79af02c2 DM |
1157 | q->empty = (list_empty(&q->out_chunk_list) && |
1158 | list_empty(&q->control_chunk_list) && | |
1159 | list_empty(&q->retransmit)); | |
1da177e4 LT |
1160 | if (!q->empty) |
1161 | goto finish; | |
1162 | ||
1163 | list_for_each(pos, transport_list) { | |
1164 | transport = list_entry(pos, struct sctp_transport, | |
1165 | transports); | |
1166 | q->empty = q->empty && list_empty(&transport->transmitted); | |
1167 | if (!q->empty) | |
1168 | goto finish; | |
1169 | } | |
1170 | ||
1171 | SCTP_DEBUG_PRINTK("sack queue is empty.\n"); | |
1172 | finish: | |
1173 | return q->empty; | |
1174 | } | |
1175 | ||
1176 | /* Is the outqueue empty? */ | |
1177 | int sctp_outq_is_empty(const struct sctp_outq *q) | |
1178 | { | |
1179 | return q->empty; | |
1180 | } | |
1181 | ||
1182 | /******************************************************************** | |
1183 | * 2nd Level Abstractions | |
1184 | ********************************************************************/ | |
1185 | ||
1186 | /* Go through a transport's transmitted list or the association's retransmit | |
1187 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1188 | * The retransmit list will not have an associated transport. | |
1189 | * | |
1190 | * I added coherent debug information output. --xguo | |
1191 | * | |
1192 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1193 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1194 | * KEPT TSN6-TSN7, etc. | |
1195 | */ | |
1196 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1197 | struct list_head *transmitted_queue, | |
1198 | struct sctp_transport *transport, | |
1199 | struct sctp_sackhdr *sack, | |
1200 | __u32 highest_new_tsn_in_sack) | |
1201 | { | |
1202 | struct list_head *lchunk; | |
1203 | struct sctp_chunk *tchunk; | |
1204 | struct list_head tlist; | |
1205 | __u32 tsn; | |
1206 | __u32 sack_ctsn; | |
1207 | __u32 rtt; | |
1208 | __u8 restart_timer = 0; | |
1209 | int bytes_acked = 0; | |
1210 | ||
1211 | /* These state variables are for coherent debug output. --xguo */ | |
1212 | ||
1213 | #if SCTP_DEBUG | |
1214 | __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */ | |
1215 | __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */ | |
1216 | __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */ | |
1217 | __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */ | |
1218 | ||
1219 | /* 0 : The last TSN was ACKed. | |
1220 | * 1 : The last TSN was NOT ACKed (i.e. KEPT). | |
1221 | * -1: We need to initialize. | |
1222 | */ | |
1223 | int dbg_prt_state = -1; | |
1224 | #endif /* SCTP_DEBUG */ | |
1225 | ||
1226 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
1227 | ||
1228 | INIT_LIST_HEAD(&tlist); | |
1229 | ||
1230 | /* The while loop will skip empty transmitted queues. */ | |
1231 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1232 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1233 | transmitted_list); | |
1234 | ||
1235 | if (sctp_chunk_abandoned(tchunk)) { | |
1236 | /* Move the chunk to abandoned list. */ | |
1237 | sctp_insert_list(&q->abandoned, lchunk); | |
1238 | continue; | |
1239 | } | |
1240 | ||
1241 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1242 | if (sctp_acked(sack, tsn)) { | |
1243 | /* If this queue is the retransmit queue, the | |
1244 | * retransmit timer has already reclaimed | |
1245 | * the outstanding bytes for this chunk, so only | |
1246 | * count bytes associated with a transport. | |
1247 | */ | |
1248 | if (transport) { | |
1249 | /* If this chunk is being used for RTT | |
1250 | * measurement, calculate the RTT and update | |
1251 | * the RTO using this value. | |
1252 | * | |
1253 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1254 | * MUST NOT be made using packets that were | |
1255 | * retransmitted (and thus for which it is | |
1256 | * ambiguous whether the reply was for the | |
1257 | * first instance of the packet or a later | |
1258 | * instance). | |
1259 | */ | |
1260 | if (!tchunk->tsn_gap_acked && | |
1261 | !tchunk->resent && | |
1262 | tchunk->rtt_in_progress) { | |
1263 | rtt = jiffies - tchunk->sent_at; | |
1264 | sctp_transport_update_rto(transport, | |
1265 | rtt); | |
1266 | } | |
1267 | } | |
1268 | if (TSN_lte(tsn, sack_ctsn)) { | |
1269 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1270 | * | |
1271 | * R3) Whenever a SACK is received | |
1272 | * that acknowledges the DATA chunk | |
1273 | * with the earliest outstanding TSN | |
1274 | * for that address, restart T3-rtx | |
1275 | * timer for that address with its | |
1276 | * current RTO. | |
1277 | */ | |
1278 | restart_timer = 1; | |
1279 | ||
1280 | if (!tchunk->tsn_gap_acked) { | |
1281 | tchunk->tsn_gap_acked = 1; | |
1282 | bytes_acked += sctp_data_size(tchunk); | |
1283 | /* | |
1284 | * SFR-CACC algorithm: | |
1285 | * 2) If the SACK contains gap acks | |
1286 | * and the flag CHANGEOVER_ACTIVE is | |
1287 | * set the receiver of the SACK MUST | |
1288 | * take the following action: | |
1289 | * | |
1290 | * B) For each TSN t being acked that | |
1291 | * has not been acked in any SACK so | |
1292 | * far, set cacc_saw_newack to 1 for | |
1293 | * the destination that the TSN was | |
1294 | * sent to. | |
1295 | */ | |
1296 | if (transport && | |
1297 | sack->num_gap_ack_blocks && | |
1298 | q->asoc->peer.primary_path->cacc. | |
1299 | changeover_active) | |
1300 | transport->cacc.cacc_saw_newack | |
1301 | = 1; | |
1302 | } | |
1303 | ||
1304 | list_add_tail(&tchunk->transmitted_list, | |
1305 | &q->sacked); | |
1306 | } else { | |
1307 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1308 | * M2) Each time a SACK arrives reporting | |
1309 | * 'Stray DATA chunk(s)' record the highest TSN | |
1310 | * reported as newly acknowledged, call this | |
1311 | * value 'HighestTSNinSack'. A newly | |
1312 | * acknowledged DATA chunk is one not | |
1313 | * previously acknowledged in a SACK. | |
1314 | * | |
1315 | * When the SCTP sender of data receives a SACK | |
1316 | * chunk that acknowledges, for the first time, | |
1317 | * the receipt of a DATA chunk, all the still | |
1318 | * unacknowledged DATA chunks whose TSN is | |
1319 | * older than that newly acknowledged DATA | |
1320 | * chunk, are qualified as 'Stray DATA chunks'. | |
1321 | */ | |
1322 | if (!tchunk->tsn_gap_acked) { | |
1323 | tchunk->tsn_gap_acked = 1; | |
1324 | bytes_acked += sctp_data_size(tchunk); | |
1325 | } | |
1326 | list_add_tail(lchunk, &tlist); | |
1327 | } | |
1328 | ||
1329 | #if SCTP_DEBUG | |
1330 | switch (dbg_prt_state) { | |
1331 | case 0: /* last TSN was ACKed */ | |
1332 | if (dbg_last_ack_tsn + 1 == tsn) { | |
1333 | /* This TSN belongs to the | |
1334 | * current ACK range. | |
1335 | */ | |
1336 | break; | |
1337 | } | |
1338 | ||
1339 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
1340 | /* Display the end of the | |
1341 | * current range. | |
1342 | */ | |
1343 | SCTP_DEBUG_PRINTK("-%08x", | |
1344 | dbg_last_ack_tsn); | |
1345 | } | |
1346 | ||
1347 | /* Start a new range. */ | |
1348 | SCTP_DEBUG_PRINTK(",%08x", tsn); | |
1349 | dbg_ack_tsn = tsn; | |
1350 | break; | |
1351 | ||
1352 | case 1: /* The last TSN was NOT ACKed. */ | |
1353 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
1354 | /* Display the end of current range. */ | |
1355 | SCTP_DEBUG_PRINTK("-%08x", | |
1356 | dbg_last_kept_tsn); | |
1357 | } | |
1358 | ||
1359 | SCTP_DEBUG_PRINTK("\n"); | |
1360 | ||
1361 | /* FALL THROUGH... */ | |
1362 | default: | |
1363 | /* This is the first-ever TSN we examined. */ | |
1364 | /* Start a new range of ACK-ed TSNs. */ | |
1365 | SCTP_DEBUG_PRINTK("ACKed: %08x", tsn); | |
1366 | dbg_prt_state = 0; | |
1367 | dbg_ack_tsn = tsn; | |
1368 | }; | |
1369 | ||
1370 | dbg_last_ack_tsn = tsn; | |
1371 | #endif /* SCTP_DEBUG */ | |
1372 | ||
1373 | } else { | |
1374 | if (tchunk->tsn_gap_acked) { | |
1375 | SCTP_DEBUG_PRINTK("%s: Receiver reneged on " | |
1376 | "data TSN: 0x%x\n", | |
1377 | __FUNCTION__, | |
1378 | tsn); | |
1379 | tchunk->tsn_gap_acked = 0; | |
1380 | ||
1381 | bytes_acked -= sctp_data_size(tchunk); | |
1382 | ||
1383 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1384 | * | |
1385 | * R4) Whenever a SACK is received missing a | |
1386 | * TSN that was previously acknowledged via a | |
1387 | * Gap Ack Block, start T3-rtx for the | |
1388 | * destination address to which the DATA | |
1389 | * chunk was originally | |
1390 | * transmitted if it is not already running. | |
1391 | */ | |
1392 | restart_timer = 1; | |
1393 | } | |
1394 | ||
1395 | list_add_tail(lchunk, &tlist); | |
1396 | ||
1397 | #if SCTP_DEBUG | |
1398 | /* See the above comments on ACK-ed TSNs. */ | |
1399 | switch (dbg_prt_state) { | |
1400 | case 1: | |
1401 | if (dbg_last_kept_tsn + 1 == tsn) | |
1402 | break; | |
1403 | ||
1404 | if (dbg_last_kept_tsn != dbg_kept_tsn) | |
1405 | SCTP_DEBUG_PRINTK("-%08x", | |
1406 | dbg_last_kept_tsn); | |
1407 | ||
1408 | SCTP_DEBUG_PRINTK(",%08x", tsn); | |
1409 | dbg_kept_tsn = tsn; | |
1410 | break; | |
1411 | ||
1412 | case 0: | |
1413 | if (dbg_last_ack_tsn != dbg_ack_tsn) | |
1414 | SCTP_DEBUG_PRINTK("-%08x", | |
1415 | dbg_last_ack_tsn); | |
1416 | SCTP_DEBUG_PRINTK("\n"); | |
1417 | ||
1418 | /* FALL THROUGH... */ | |
1419 | default: | |
1420 | SCTP_DEBUG_PRINTK("KEPT: %08x",tsn); | |
1421 | dbg_prt_state = 1; | |
1422 | dbg_kept_tsn = tsn; | |
1423 | }; | |
1424 | ||
1425 | dbg_last_kept_tsn = tsn; | |
1426 | #endif /* SCTP_DEBUG */ | |
1427 | } | |
1428 | } | |
1429 | ||
1430 | #if SCTP_DEBUG | |
1431 | /* Finish off the last range, displaying its ending TSN. */ | |
1432 | switch (dbg_prt_state) { | |
1433 | case 0: | |
1434 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
1435 | SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn); | |
1436 | } else { | |
1437 | SCTP_DEBUG_PRINTK("\n"); | |
1438 | } | |
1439 | break; | |
1440 | ||
1441 | case 1: | |
1442 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
1443 | SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn); | |
1444 | } else { | |
1445 | SCTP_DEBUG_PRINTK("\n"); | |
1446 | } | |
1447 | }; | |
1448 | #endif /* SCTP_DEBUG */ | |
1449 | if (transport) { | |
1450 | if (bytes_acked) { | |
1451 | /* 8.2. When an outstanding TSN is acknowledged, | |
1452 | * the endpoint shall clear the error counter of | |
1453 | * the destination transport address to which the | |
1454 | * DATA chunk was last sent. | |
1455 | * The association's overall error counter is | |
1456 | * also cleared. | |
1457 | */ | |
1458 | transport->error_count = 0; | |
1459 | transport->asoc->overall_error_count = 0; | |
1460 | ||
1461 | /* Mark the destination transport address as | |
1462 | * active if it is not so marked. | |
1463 | */ | |
3f7a87d2 | 1464 | if (transport->state == SCTP_INACTIVE) { |
1da177e4 LT |
1465 | sctp_assoc_control_transport( |
1466 | transport->asoc, | |
1467 | transport, | |
1468 | SCTP_TRANSPORT_UP, | |
1469 | SCTP_RECEIVED_SACK); | |
1470 | } | |
1471 | ||
1472 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1473 | bytes_acked); | |
1474 | ||
1475 | transport->flight_size -= bytes_acked; | |
1476 | q->outstanding_bytes -= bytes_acked; | |
1477 | } else { | |
1478 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1479 | * When a sender is doing zero window probing, it | |
1480 | * should not timeout the association if it continues | |
1481 | * to receive new packets from the receiver. The | |
1482 | * reason is that the receiver MAY keep its window | |
1483 | * closed for an indefinite time. | |
1484 | * A sender is doing zero window probing when the | |
1485 | * receiver's advertised window is zero, and there is | |
1486 | * only one data chunk in flight to the receiver. | |
1487 | */ | |
1488 | if (!q->asoc->peer.rwnd && | |
1489 | !list_empty(&tlist) && | |
1490 | (sack_ctsn+2 == q->asoc->next_tsn)) { | |
1491 | SCTP_DEBUG_PRINTK("%s: SACK received for zero " | |
1492 | "window probe: %u\n", | |
1493 | __FUNCTION__, sack_ctsn); | |
1494 | q->asoc->overall_error_count = 0; | |
1495 | transport->error_count = 0; | |
1496 | } | |
1497 | } | |
1498 | ||
1499 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1500 | * | |
1501 | * R2) Whenever all outstanding data sent to an address have | |
1502 | * been acknowledged, turn off the T3-rtx timer of that | |
1503 | * address. | |
1504 | */ | |
1505 | if (!transport->flight_size) { | |
1506 | if (timer_pending(&transport->T3_rtx_timer) && | |
1507 | del_timer(&transport->T3_rtx_timer)) { | |
1508 | sctp_transport_put(transport); | |
1509 | } | |
1510 | } else if (restart_timer) { | |
1511 | if (!mod_timer(&transport->T3_rtx_timer, | |
1512 | jiffies + transport->rto)) | |
1513 | sctp_transport_hold(transport); | |
1514 | } | |
1515 | } | |
1516 | ||
1517 | list_splice(&tlist, transmitted_queue); | |
1518 | } | |
1519 | ||
1520 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1521 | static void sctp_mark_missing(struct sctp_outq *q, | |
1522 | struct list_head *transmitted_queue, | |
1523 | struct sctp_transport *transport, | |
1524 | __u32 highest_new_tsn_in_sack, | |
1525 | int count_of_newacks) | |
1526 | { | |
1527 | struct sctp_chunk *chunk; | |
1528 | struct list_head *pos; | |
1529 | __u32 tsn; | |
1530 | char do_fast_retransmit = 0; | |
1531 | struct sctp_transport *primary = q->asoc->peer.primary_path; | |
1532 | ||
1533 | list_for_each(pos, transmitted_queue) { | |
1534 | ||
1535 | chunk = list_entry(pos, struct sctp_chunk, transmitted_list); | |
1536 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1537 | ||
1538 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1539 | * 'Unacknowledged TSN's', if the TSN number of an | |
1540 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1541 | * value, increment the 'TSN.Missing.Report' count on that | |
1542 | * chunk if it has NOT been fast retransmitted or marked for | |
1543 | * fast retransmit already. | |
1544 | */ | |
1545 | if (!chunk->fast_retransmit && | |
1546 | !chunk->tsn_gap_acked && | |
1547 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1548 | ||
1549 | /* SFR-CACC may require us to skip marking | |
1550 | * this chunk as missing. | |
1551 | */ | |
1552 | if (!transport || !sctp_cacc_skip(primary, transport, | |
1553 | count_of_newacks, tsn)) { | |
1554 | chunk->tsn_missing_report++; | |
1555 | ||
1556 | SCTP_DEBUG_PRINTK( | |
1557 | "%s: TSN 0x%x missing counter: %d\n", | |
1558 | __FUNCTION__, tsn, | |
1559 | chunk->tsn_missing_report); | |
1560 | } | |
1561 | } | |
1562 | /* | |
1563 | * M4) If any DATA chunk is found to have a | |
1564 | * 'TSN.Missing.Report' | |
1565 | * value larger than or equal to 4, mark that chunk for | |
1566 | * retransmission and start the fast retransmit procedure. | |
1567 | */ | |
1568 | ||
1569 | if (chunk->tsn_missing_report >= 4) { | |
1570 | chunk->fast_retransmit = 1; | |
1571 | do_fast_retransmit = 1; | |
1572 | } | |
1573 | } | |
1574 | ||
1575 | if (transport) { | |
1576 | if (do_fast_retransmit) | |
1577 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1578 | ||
1579 | SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, " | |
1580 | "ssthresh: %d, flight_size: %d, pba: %d\n", | |
1581 | __FUNCTION__, transport, transport->cwnd, | |
1582 | transport->ssthresh, transport->flight_size, | |
1583 | transport->partial_bytes_acked); | |
1584 | } | |
1585 | } | |
1586 | ||
1587 | /* Is the given TSN acked by this packet? */ | |
1588 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1589 | { | |
1590 | int i; | |
1591 | sctp_sack_variable_t *frags; | |
1592 | __u16 gap; | |
1593 | __u32 ctsn = ntohl(sack->cum_tsn_ack); | |
1594 | ||
1595 | if (TSN_lte(tsn, ctsn)) | |
1596 | goto pass; | |
1597 | ||
1598 | /* 3.3.4 Selective Acknowledgement (SACK) (3): | |
1599 | * | |
1600 | * Gap Ack Blocks: | |
1601 | * These fields contain the Gap Ack Blocks. They are repeated | |
1602 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1603 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1604 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1605 | * Ack + Gap Ack Block Start) and less than or equal to | |
1606 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1607 | * Block are assumed to have been received correctly. | |
1608 | */ | |
1609 | ||
1610 | frags = sack->variable; | |
1611 | gap = tsn - ctsn; | |
1612 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { | |
1613 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && | |
1614 | TSN_lte(gap, ntohs(frags[i].gab.end))) | |
1615 | goto pass; | |
1616 | } | |
1617 | ||
1618 | return 0; | |
1619 | pass: | |
1620 | return 1; | |
1621 | } | |
1622 | ||
1623 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
1624 | int nskips, __u16 stream) | |
1625 | { | |
1626 | int i; | |
1627 | ||
1628 | for (i = 0; i < nskips; i++) { | |
1629 | if (skiplist[i].stream == stream) | |
1630 | return i; | |
1631 | } | |
1632 | return i; | |
1633 | } | |
1634 | ||
1635 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
1636 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) | |
1637 | { | |
1638 | struct sctp_association *asoc = q->asoc; | |
1639 | struct sctp_chunk *ftsn_chunk = NULL; | |
1640 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1641 | int nskips = 0; | |
1642 | int skip_pos = 0; | |
1643 | __u32 tsn; | |
1644 | struct sctp_chunk *chunk; | |
1645 | struct list_head *lchunk, *temp; | |
1646 | ||
1647 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the | |
1648 | * received SACK. | |
1649 | * | |
1650 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update | |
1651 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1652 | */ | |
1653 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1654 | asoc->adv_peer_ack_point = ctsn; | |
1655 | ||
1656 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1657 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1658 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1659 | * shown in the following example: | |
1660 | * | |
1661 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1662 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
1663 | * | |
1664 | * out-queue at the end of ==> out-queue after Adv.Ack.Point | |
1665 | * normal SACK processing local advancement | |
1666 | * ... ... | |
1667 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1668 | * 103 abandoned 103 abandoned | |
1669 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1670 | * 105 105 | |
1671 | * 106 acked 106 acked | |
1672 | * ... ... | |
1673 | * | |
1674 | * In this example, the data sender successfully advanced the | |
1675 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1676 | */ | |
1677 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1678 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1679 | transmitted_list); | |
1680 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1681 | ||
1682 | /* Remove any chunks in the abandoned queue that are acked by | |
1683 | * the ctsn. | |
1684 | */ | |
1685 | if (TSN_lte(tsn, ctsn)) { | |
1686 | list_del_init(lchunk); | |
1687 | if (!chunk->tsn_gap_acked) { | |
79af02c2 DM |
1688 | chunk->transport->flight_size -= |
1689 | sctp_data_size(chunk); | |
1690 | q->outstanding_bytes -= sctp_data_size(chunk); | |
1da177e4 LT |
1691 | } |
1692 | sctp_chunk_free(chunk); | |
1693 | } else { | |
1694 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1695 | asoc->adv_peer_ack_point = tsn; | |
1696 | if (chunk->chunk_hdr->flags & | |
1697 | SCTP_DATA_UNORDERED) | |
1698 | continue; | |
1699 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1700 | nskips, | |
1701 | chunk->subh.data_hdr->stream); | |
1702 | ftsn_skip_arr[skip_pos].stream = | |
1703 | chunk->subh.data_hdr->stream; | |
1704 | ftsn_skip_arr[skip_pos].ssn = | |
1705 | chunk->subh.data_hdr->ssn; | |
1706 | if (skip_pos == nskips) | |
1707 | nskips++; | |
1708 | if (nskips == 10) | |
1709 | break; | |
1710 | } else | |
1711 | break; | |
1712 | } | |
1713 | } | |
1714 | ||
1715 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1716 | * is greater than the Cumulative TSN ACK carried in the received | |
1717 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1718 | * chunk containing the latest value of the | |
1719 | * "Advanced.Peer.Ack.Point". | |
1720 | * | |
1721 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1722 | * list each stream and sequence number in the forwarded TSN. This | |
1723 | * information will enable the receiver to easily find any | |
1724 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1725 | * SHOULD only be reported once; this means that if multiple | |
1726 | * abandoned messages occur in the same stream then only the | |
1727 | * highest abandoned stream sequence number is reported. If the | |
1728 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1729 | * the sender of the FORWARD TSN SHOULD lower the | |
1730 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1731 | * single MTU. | |
1732 | */ | |
1733 | if (asoc->adv_peer_ack_point > ctsn) | |
1734 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
1735 | nskips, &ftsn_skip_arr[0]); | |
1736 | ||
1737 | if (ftsn_chunk) { | |
79af02c2 | 1738 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
1da177e4 LT |
1739 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
1740 | } | |
1741 | } |