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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 | ||
145ce502 JP |
49 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
50 | ||
1da177e4 LT |
51 | #include <linux/types.h> |
52 | #include <linux/list.h> /* For struct list_head */ | |
53 | #include <linux/socket.h> | |
54 | #include <linux/ip.h> | |
5a0e3ad6 | 55 | #include <linux/slab.h> |
1da177e4 LT |
56 | #include <net/sock.h> /* For skb_set_owner_w */ |
57 | ||
58 | #include <net/sctp/sctp.h> | |
59 | #include <net/sctp/sm.h> | |
60 | ||
61 | /* Declare internal functions here. */ | |
62 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); | |
63 | static void sctp_check_transmitted(struct sctp_outq *q, | |
64 | struct list_head *transmitted_queue, | |
65 | struct sctp_transport *transport, | |
66 | struct sctp_sackhdr *sack, | |
bfa0d984 | 67 | __u32 *highest_new_tsn); |
1da177e4 LT |
68 | |
69 | static void sctp_mark_missing(struct sctp_outq *q, | |
70 | struct list_head *transmitted_queue, | |
71 | struct sctp_transport *transport, | |
72 | __u32 highest_new_tsn, | |
73 | int count_of_newacks); | |
74 | ||
75 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); | |
76 | ||
abd0b198 AB |
77 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout); |
78 | ||
1da177e4 LT |
79 | /* Add data to the front of the queue. */ |
80 | static inline void sctp_outq_head_data(struct sctp_outq *q, | |
81 | struct sctp_chunk *ch) | |
82 | { | |
79af02c2 | 83 | list_add(&ch->list, &q->out_chunk_list); |
1da177e4 | 84 | q->out_qlen += ch->skb->len; |
1da177e4 LT |
85 | } |
86 | ||
87 | /* Take data from the front of the queue. */ | |
88 | static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) | |
89 | { | |
79af02c2 DM |
90 | struct sctp_chunk *ch = NULL; |
91 | ||
92 | if (!list_empty(&q->out_chunk_list)) { | |
93 | struct list_head *entry = q->out_chunk_list.next; | |
94 | ||
95 | ch = list_entry(entry, struct sctp_chunk, list); | |
96 | list_del_init(entry); | |
1da177e4 | 97 | q->out_qlen -= ch->skb->len; |
79af02c2 | 98 | } |
1da177e4 LT |
99 | return ch; |
100 | } | |
101 | /* Add data chunk to the end of the queue. */ | |
102 | static inline void sctp_outq_tail_data(struct sctp_outq *q, | |
103 | struct sctp_chunk *ch) | |
104 | { | |
79af02c2 | 105 | list_add_tail(&ch->list, &q->out_chunk_list); |
1da177e4 | 106 | q->out_qlen += ch->skb->len; |
1da177e4 LT |
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, | |
25985edc | 180 | * then the sender MUST further execute steps 3.1 and |
1da177e4 LT |
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 | |
25985edc | 186 | * the sender SHOULD increment missing report count for |
1da177e4 LT |
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; | |
62aeaff5 | 548 | int fast_rtx; |
1da177e4 | 549 | int error = 0; |
62aeaff5 | 550 | int timer = 0; |
8b750ce5 | 551 | int done = 0; |
1da177e4 | 552 | |
1da177e4 | 553 | lqueue = &q->retransmit; |
62aeaff5 | 554 | fast_rtx = q->fast_rtx; |
1da177e4 | 555 | |
8b750ce5 VY |
556 | /* This loop handles time-out retransmissions, fast retransmissions, |
557 | * and retransmissions due to opening of whindow. | |
558 | * | |
559 | * RFC 2960 6.3.3 Handle T3-rtx Expiration | |
1da177e4 LT |
560 | * |
561 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
562 | * outstanding DATA chunks for the address for which the | |
563 | * T3-rtx has expired will fit into a single packet, subject | |
564 | * to the MTU constraint for the path corresponding to the | |
565 | * destination transport address to which the retransmission | |
566 | * is being sent (this may be different from the address for | |
567 | * which the timer expires [see Section 6.4]). Call this value | |
568 | * K. Bundle and retransmit those K DATA chunks in a single | |
569 | * packet to the destination endpoint. | |
570 | * | |
571 | * [Just to be painfully clear, if we are retransmitting | |
572 | * because a timeout just happened, we should send only ONE | |
573 | * packet of retransmitted data.] | |
8b750ce5 VY |
574 | * |
575 | * For fast retransmissions we also send only ONE packet. However, | |
576 | * if we are just flushing the queue due to open window, we'll | |
577 | * try to send as much as possible. | |
1da177e4 | 578 | */ |
8b750ce5 | 579 | list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { |
1da177e4 LT |
580 | |
581 | /* Make sure that Gap Acked TSNs are not retransmitted. A | |
582 | * simple approach is just to move such TSNs out of the | |
583 | * way and into a 'transmitted' queue and skip to the | |
584 | * next chunk. | |
585 | */ | |
586 | if (chunk->tsn_gap_acked) { | |
8b750ce5 VY |
587 | list_del(&chunk->transmitted_list); |
588 | list_add_tail(&chunk->transmitted_list, | |
589 | &transport->transmitted); | |
1da177e4 LT |
590 | continue; |
591 | } | |
592 | ||
8b750ce5 VY |
593 | /* If we are doing fast retransmit, ignore non-fast_rtransmit |
594 | * chunks | |
595 | */ | |
596 | if (fast_rtx && !chunk->fast_retransmit) | |
597 | continue; | |
598 | ||
bc4f841a | 599 | redo: |
1da177e4 LT |
600 | /* Attempt to append this chunk to the packet. */ |
601 | status = sctp_packet_append_chunk(pkt, chunk); | |
602 | ||
603 | switch (status) { | |
604 | case SCTP_XMIT_PMTU_FULL: | |
bc4f841a WY |
605 | if (!pkt->has_data && !pkt->has_cookie_echo) { |
606 | /* If this packet did not contain DATA then | |
607 | * retransmission did not happen, so do it | |
608 | * again. We'll ignore the error here since | |
609 | * control chunks are already freed so there | |
610 | * is nothing we can do. | |
611 | */ | |
612 | sctp_packet_transmit(pkt); | |
613 | goto redo; | |
614 | } | |
615 | ||
1da177e4 | 616 | /* Send this packet. */ |
62aeaff5 | 617 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
618 | |
619 | /* If we are retransmitting, we should only | |
620 | * send a single packet. | |
621 | */ | |
8b750ce5 VY |
622 | if (rtx_timeout || fast_rtx) |
623 | done = 1; | |
1da177e4 | 624 | |
8b750ce5 | 625 | /* Bundle next chunk in the next round. */ |
1da177e4 LT |
626 | break; |
627 | ||
628 | case SCTP_XMIT_RWND_FULL: | |
d808ad9a | 629 | /* Send this packet. */ |
62aeaff5 | 630 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
631 | |
632 | /* Stop sending DATA as there is no more room | |
633 | * at the receiver. | |
634 | */ | |
8b750ce5 | 635 | done = 1; |
1da177e4 LT |
636 | break; |
637 | ||
638 | case SCTP_XMIT_NAGLE_DELAY: | |
d808ad9a | 639 | /* Send this packet. */ |
62aeaff5 | 640 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
641 | |
642 | /* Stop sending DATA because of nagle delay. */ | |
8b750ce5 | 643 | done = 1; |
1da177e4 LT |
644 | break; |
645 | ||
646 | default: | |
647 | /* The append was successful, so add this chunk to | |
648 | * the transmitted list. | |
649 | */ | |
8b750ce5 VY |
650 | list_del(&chunk->transmitted_list); |
651 | list_add_tail(&chunk->transmitted_list, | |
652 | &transport->transmitted); | |
1da177e4 | 653 | |
d808ad9a | 654 | /* Mark the chunk as ineligible for fast retransmit |
1da177e4 LT |
655 | * after it is retransmitted. |
656 | */ | |
c226ef9b NH |
657 | if (chunk->fast_retransmit == SCTP_NEED_FRTX) |
658 | chunk->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 | 659 | |
1da177e4 | 660 | q->empty = 0; |
1da177e4 | 661 | break; |
3ff50b79 | 662 | } |
1da177e4 | 663 | |
62aeaff5 VY |
664 | /* Set the timer if there were no errors */ |
665 | if (!error && !timer) | |
666 | timer = 1; | |
667 | ||
8b750ce5 VY |
668 | if (done) |
669 | break; | |
670 | } | |
671 | ||
672 | /* If we are here due to a retransmit timeout or a fast | |
673 | * retransmit and if there are any chunks left in the retransmit | |
674 | * queue that could not fit in the PMTU sized packet, they need | |
675 | * to be marked as ineligible for a subsequent fast retransmit. | |
676 | */ | |
677 | if (rtx_timeout || fast_rtx) { | |
678 | list_for_each_entry(chunk1, lqueue, transmitted_list) { | |
c226ef9b NH |
679 | if (chunk1->fast_retransmit == SCTP_NEED_FRTX) |
680 | chunk1->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 LT |
681 | } |
682 | } | |
683 | ||
62aeaff5 VY |
684 | *start_timer = timer; |
685 | ||
686 | /* Clear fast retransmit hint */ | |
687 | if (fast_rtx) | |
688 | q->fast_rtx = 0; | |
689 | ||
1da177e4 LT |
690 | return error; |
691 | } | |
692 | ||
693 | /* Cork the outqueue so queued chunks are really queued. */ | |
694 | int sctp_outq_uncork(struct sctp_outq *q) | |
695 | { | |
696 | int error = 0; | |
7d54dc68 | 697 | if (q->cork) |
1da177e4 | 698 | q->cork = 0; |
7d54dc68 | 699 | error = sctp_outq_flush(q, 0); |
1da177e4 LT |
700 | return error; |
701 | } | |
702 | ||
2e3216cd | 703 | |
1da177e4 LT |
704 | /* |
705 | * Try to flush an outqueue. | |
706 | * | |
707 | * Description: Send everything in q which we legally can, subject to | |
708 | * congestion limitations. | |
709 | * * Note: This function can be called from multiple contexts so appropriate | |
710 | * locking concerns must be made. Today we use the sock lock to protect | |
711 | * this function. | |
712 | */ | |
abd0b198 | 713 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) |
1da177e4 LT |
714 | { |
715 | struct sctp_packet *packet; | |
716 | struct sctp_packet singleton; | |
717 | struct sctp_association *asoc = q->asoc; | |
718 | __u16 sport = asoc->base.bind_addr.port; | |
719 | __u16 dport = asoc->peer.port; | |
720 | __u32 vtag = asoc->peer.i.init_tag; | |
1da177e4 LT |
721 | struct sctp_transport *transport = NULL; |
722 | struct sctp_transport *new_transport; | |
79af02c2 | 723 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
724 | sctp_xmit_t status; |
725 | int error = 0; | |
726 | int start_timer = 0; | |
2e3216cd | 727 | int one_packet = 0; |
1da177e4 LT |
728 | |
729 | /* These transports have chunks to send. */ | |
730 | struct list_head transport_list; | |
731 | struct list_head *ltransport; | |
732 | ||
733 | INIT_LIST_HEAD(&transport_list); | |
734 | packet = NULL; | |
735 | ||
736 | /* | |
737 | * 6.10 Bundling | |
738 | * ... | |
739 | * When bundling control chunks with DATA chunks, an | |
740 | * endpoint MUST place control chunks first in the outbound | |
741 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
742 | * within a SCTP packet in increasing order of TSN. | |
743 | * ... | |
744 | */ | |
745 | ||
79af02c2 DM |
746 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
747 | list_del_init(&chunk->list); | |
748 | ||
1da177e4 LT |
749 | /* Pick the right transport to use. */ |
750 | new_transport = chunk->transport; | |
751 | ||
752 | if (!new_transport) { | |
a08de64d VY |
753 | /* |
754 | * If we have a prior transport pointer, see if | |
755 | * the destination address of the chunk | |
756 | * matches the destination address of the | |
757 | * current transport. If not a match, then | |
758 | * try to look up the transport with a given | |
759 | * destination address. We do this because | |
760 | * after processing ASCONFs, we may have new | |
761 | * transports created. | |
762 | */ | |
763 | if (transport && | |
764 | sctp_cmp_addr_exact(&chunk->dest, | |
765 | &transport->ipaddr)) | |
766 | new_transport = transport; | |
767 | else | |
768 | new_transport = sctp_assoc_lookup_paddr(asoc, | |
769 | &chunk->dest); | |
770 | ||
771 | /* if we still don't have a new transport, then | |
772 | * use the current active path. | |
773 | */ | |
774 | if (!new_transport) | |
775 | new_transport = asoc->peer.active_path; | |
ad8fec17 SS |
776 | } else if ((new_transport->state == SCTP_INACTIVE) || |
777 | (new_transport->state == SCTP_UNCONFIRMED)) { | |
3f7a87d2 FF |
778 | /* If the chunk is Heartbeat or Heartbeat Ack, |
779 | * send it to chunk->transport, even if it's | |
1da177e4 LT |
780 | * inactive. |
781 | * | |
782 | * 3.3.6 Heartbeat Acknowledgement: | |
d808ad9a | 783 | * ... |
1da177e4 LT |
784 | * A HEARTBEAT ACK is always sent to the source IP |
785 | * address of the IP datagram containing the | |
786 | * HEARTBEAT chunk to which this ack is responding. | |
d808ad9a | 787 | * ... |
a08de64d VY |
788 | * |
789 | * ASCONF_ACKs also must be sent to the source. | |
1da177e4 LT |
790 | */ |
791 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && | |
a08de64d VY |
792 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK && |
793 | chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK) | |
1da177e4 LT |
794 | new_transport = asoc->peer.active_path; |
795 | } | |
796 | ||
797 | /* Are we switching transports? | |
798 | * Take care of transport locks. | |
799 | */ | |
800 | if (new_transport != transport) { | |
801 | transport = new_transport; | |
802 | if (list_empty(&transport->send_ready)) { | |
803 | list_add_tail(&transport->send_ready, | |
804 | &transport_list); | |
805 | } | |
806 | packet = &transport->packet; | |
807 | sctp_packet_config(packet, vtag, | |
808 | asoc->peer.ecn_capable); | |
809 | } | |
810 | ||
811 | switch (chunk->chunk_hdr->type) { | |
812 | /* | |
813 | * 6.10 Bundling | |
814 | * ... | |
815 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
816 | * COMPLETE with any other chunks. [Send them immediately.] | |
817 | */ | |
818 | case SCTP_CID_INIT: | |
819 | case SCTP_CID_INIT_ACK: | |
820 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
821 | sctp_packet_init(&singleton, transport, sport, dport); | |
822 | sctp_packet_config(&singleton, vtag, 0); | |
823 | sctp_packet_append_chunk(&singleton, chunk); | |
824 | error = sctp_packet_transmit(&singleton); | |
825 | if (error < 0) | |
826 | return error; | |
827 | break; | |
828 | ||
829 | case SCTP_CID_ABORT: | |
f4ad85ca GJ |
830 | if (sctp_test_T_bit(chunk)) { |
831 | packet->vtag = asoc->c.my_vtag; | |
832 | } | |
2e3216cd VY |
833 | /* The following chunks are "response" chunks, i.e. |
834 | * they are generated in response to something we | |
835 | * received. If we are sending these, then we can | |
836 | * send only 1 packet containing these chunks. | |
837 | */ | |
1da177e4 | 838 | case SCTP_CID_HEARTBEAT_ACK: |
1da177e4 | 839 | case SCTP_CID_SHUTDOWN_ACK: |
1da177e4 | 840 | case SCTP_CID_COOKIE_ACK: |
2e3216cd VY |
841 | case SCTP_CID_COOKIE_ECHO: |
842 | case SCTP_CID_ERROR: | |
1da177e4 | 843 | case SCTP_CID_ECN_CWR: |
1da177e4 | 844 | case SCTP_CID_ASCONF_ACK: |
2e3216cd | 845 | one_packet = 1; |
25985edc | 846 | /* Fall through */ |
2e3216cd VY |
847 | |
848 | case SCTP_CID_SACK: | |
849 | case SCTP_CID_HEARTBEAT: | |
850 | case SCTP_CID_SHUTDOWN: | |
851 | case SCTP_CID_ECN_ECNE: | |
852 | case SCTP_CID_ASCONF: | |
1da177e4 | 853 | case SCTP_CID_FWD_TSN: |
2e3216cd VY |
854 | status = sctp_packet_transmit_chunk(packet, chunk, |
855 | one_packet); | |
856 | if (status != SCTP_XMIT_OK) { | |
857 | /* put the chunk back */ | |
858 | list_add(&chunk->list, &q->control_chunk_list); | |
bd69b981 WY |
859 | } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) { |
860 | /* PR-SCTP C5) If a FORWARD TSN is sent, the | |
861 | * sender MUST assure that at least one T3-rtx | |
862 | * timer is running. | |
863 | */ | |
d9efc223 | 864 | sctp_transport_reset_timers(transport); |
2e3216cd | 865 | } |
1da177e4 LT |
866 | break; |
867 | ||
868 | default: | |
869 | /* We built a chunk with an illegal type! */ | |
870 | BUG(); | |
3ff50b79 | 871 | } |
1da177e4 LT |
872 | } |
873 | ||
874 | /* Is it OK to send data chunks? */ | |
875 | switch (asoc->state) { | |
876 | case SCTP_STATE_COOKIE_ECHOED: | |
877 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
878 | * chunk. | |
879 | */ | |
880 | if (!packet || !packet->has_cookie_echo) | |
881 | break; | |
882 | ||
883 | /* fallthru */ | |
884 | case SCTP_STATE_ESTABLISHED: | |
885 | case SCTP_STATE_SHUTDOWN_PENDING: | |
886 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
887 | /* | |
888 | * RFC 2960 6.1 Transmission of DATA Chunks | |
889 | * | |
890 | * C) When the time comes for the sender to transmit, | |
891 | * before sending new DATA chunks, the sender MUST | |
892 | * first transmit any outstanding DATA chunks which | |
893 | * are marked for retransmission (limited by the | |
894 | * current cwnd). | |
895 | */ | |
896 | if (!list_empty(&q->retransmit)) { | |
897 | if (transport == asoc->peer.retran_path) | |
898 | goto retran; | |
899 | ||
900 | /* Switch transports & prepare the packet. */ | |
901 | ||
902 | transport = asoc->peer.retran_path; | |
903 | ||
904 | if (list_empty(&transport->send_ready)) { | |
905 | list_add_tail(&transport->send_ready, | |
906 | &transport_list); | |
907 | } | |
908 | ||
909 | packet = &transport->packet; | |
910 | sctp_packet_config(packet, vtag, | |
911 | asoc->peer.ecn_capable); | |
912 | retran: | |
913 | error = sctp_outq_flush_rtx(q, packet, | |
914 | rtx_timeout, &start_timer); | |
915 | ||
916 | if (start_timer) | |
d9efc223 | 917 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
918 | |
919 | /* This can happen on COOKIE-ECHO resend. Only | |
920 | * one chunk can get bundled with a COOKIE-ECHO. | |
921 | */ | |
922 | if (packet->has_cookie_echo) | |
923 | goto sctp_flush_out; | |
924 | ||
925 | /* Don't send new data if there is still data | |
926 | * waiting to retransmit. | |
927 | */ | |
928 | if (!list_empty(&q->retransmit)) | |
929 | goto sctp_flush_out; | |
930 | } | |
931 | ||
46d5a808 VY |
932 | /* Apply Max.Burst limitation to the current transport in |
933 | * case it will be used for new data. We are going to | |
934 | * rest it before we return, but we want to apply the limit | |
935 | * to the currently queued data. | |
936 | */ | |
937 | if (transport) | |
938 | sctp_transport_burst_limited(transport); | |
939 | ||
1da177e4 | 940 | /* Finally, transmit new packets. */ |
1da177e4 LT |
941 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
942 | /* RFC 2960 6.5 Every DATA chunk MUST carry a valid | |
943 | * stream identifier. | |
944 | */ | |
945 | if (chunk->sinfo.sinfo_stream >= | |
946 | asoc->c.sinit_num_ostreams) { | |
947 | ||
948 | /* Mark as failed send. */ | |
949 | sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); | |
950 | sctp_chunk_free(chunk); | |
951 | continue; | |
952 | } | |
953 | ||
954 | /* Has this chunk expired? */ | |
955 | if (sctp_chunk_abandoned(chunk)) { | |
956 | sctp_chunk_fail(chunk, 0); | |
957 | sctp_chunk_free(chunk); | |
958 | continue; | |
959 | } | |
960 | ||
961 | /* If there is a specified transport, use it. | |
962 | * Otherwise, we want to use the active path. | |
963 | */ | |
964 | new_transport = chunk->transport; | |
3f7a87d2 | 965 | if (!new_transport || |
ad8fec17 SS |
966 | ((new_transport->state == SCTP_INACTIVE) || |
967 | (new_transport->state == SCTP_UNCONFIRMED))) | |
1da177e4 LT |
968 | new_transport = asoc->peer.active_path; |
969 | ||
970 | /* Change packets if necessary. */ | |
971 | if (new_transport != transport) { | |
972 | transport = new_transport; | |
973 | ||
974 | /* Schedule to have this transport's | |
975 | * packet flushed. | |
976 | */ | |
977 | if (list_empty(&transport->send_ready)) { | |
978 | list_add_tail(&transport->send_ready, | |
979 | &transport_list); | |
980 | } | |
981 | ||
982 | packet = &transport->packet; | |
983 | sctp_packet_config(packet, vtag, | |
984 | asoc->peer.ecn_capable); | |
46d5a808 VY |
985 | /* We've switched transports, so apply the |
986 | * Burst limit to the new transport. | |
987 | */ | |
988 | sctp_transport_burst_limited(transport); | |
1da177e4 LT |
989 | } |
990 | ||
991 | SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ", | |
992 | q, chunk, | |
993 | chunk && chunk->chunk_hdr ? | |
994 | sctp_cname(SCTP_ST_CHUNK( | |
995 | chunk->chunk_hdr->type)) | |
996 | : "Illegal Chunk"); | |
997 | ||
998 | SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head " | |
999 | "%p skb->users %d.\n", | |
1000 | ntohl(chunk->subh.data_hdr->tsn), | |
1001 | chunk->skb ?chunk->skb->head : NULL, | |
1002 | chunk->skb ? | |
1003 | atomic_read(&chunk->skb->users) : -1); | |
1004 | ||
1005 | /* Add the chunk to the packet. */ | |
2e3216cd | 1006 | status = sctp_packet_transmit_chunk(packet, chunk, 0); |
1da177e4 LT |
1007 | |
1008 | switch (status) { | |
1009 | case SCTP_XMIT_PMTU_FULL: | |
1010 | case SCTP_XMIT_RWND_FULL: | |
1011 | case SCTP_XMIT_NAGLE_DELAY: | |
1012 | /* We could not append this chunk, so put | |
1013 | * the chunk back on the output queue. | |
1014 | */ | |
1015 | SCTP_DEBUG_PRINTK("sctp_outq_flush: could " | |
1016 | "not transmit TSN: 0x%x, status: %d\n", | |
1017 | ntohl(chunk->subh.data_hdr->tsn), | |
1018 | status); | |
1019 | sctp_outq_head_data(q, chunk); | |
1020 | goto sctp_flush_out; | |
1021 | break; | |
1022 | ||
1023 | case SCTP_XMIT_OK: | |
b93d6471 WY |
1024 | /* The sender is in the SHUTDOWN-PENDING state, |
1025 | * The sender MAY set the I-bit in the DATA | |
1026 | * chunk header. | |
1027 | */ | |
1028 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) | |
1029 | chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; | |
1030 | ||
1da177e4 LT |
1031 | break; |
1032 | ||
1033 | default: | |
1034 | BUG(); | |
1035 | } | |
1036 | ||
d808ad9a | 1037 | /* BUG: We assume that the sctp_packet_transmit() |
1da177e4 LT |
1038 | * call below will succeed all the time and add the |
1039 | * chunk to the transmitted list and restart the | |
1040 | * timers. | |
1041 | * It is possible that the call can fail under OOM | |
1042 | * conditions. | |
1043 | * | |
1044 | * Is this really a problem? Won't this behave | |
1045 | * like a lost TSN? | |
1046 | */ | |
1047 | list_add_tail(&chunk->transmitted_list, | |
1048 | &transport->transmitted); | |
1049 | ||
d9efc223 | 1050 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
1051 | |
1052 | q->empty = 0; | |
1053 | ||
1054 | /* Only let one DATA chunk get bundled with a | |
1055 | * COOKIE-ECHO chunk. | |
1056 | */ | |
1057 | if (packet->has_cookie_echo) | |
1058 | goto sctp_flush_out; | |
1059 | } | |
1060 | break; | |
1061 | ||
1062 | default: | |
1063 | /* Do nothing. */ | |
1064 | break; | |
1065 | } | |
1066 | ||
1067 | sctp_flush_out: | |
1068 | ||
1069 | /* Before returning, examine all the transports touched in | |
1070 | * this call. Right now, we bluntly force clear all the | |
1071 | * transports. Things might change after we implement Nagle. | |
1072 | * But such an examination is still required. | |
1073 | * | |
1074 | * --xguo | |
1075 | */ | |
1076 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) { | |
1077 | struct sctp_transport *t = list_entry(ltransport, | |
1078 | struct sctp_transport, | |
1079 | send_ready); | |
1080 | packet = &t->packet; | |
1081 | if (!sctp_packet_empty(packet)) | |
1082 | error = sctp_packet_transmit(packet); | |
46d5a808 VY |
1083 | |
1084 | /* Clear the burst limited state, if any */ | |
1085 | sctp_transport_burst_reset(t); | |
1da177e4 LT |
1086 | } |
1087 | ||
1088 | return error; | |
1089 | } | |
1090 | ||
1091 | /* Update unack_data based on the incoming SACK chunk */ | |
1092 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
1093 | struct sctp_sackhdr *sack) | |
1094 | { | |
1095 | sctp_sack_variable_t *frags; | |
1096 | __u16 unack_data; | |
1097 | int i; | |
1098 | ||
1099 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
1100 | ||
1101 | frags = sack->variable; | |
1102 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
1103 | unack_data -= ((ntohs(frags[i].gab.end) - | |
1104 | ntohs(frags[i].gab.start) + 1)); | |
1105 | } | |
1106 | ||
1107 | assoc->unack_data = unack_data; | |
1108 | } | |
1109 | ||
1da177e4 LT |
1110 | /* This is where we REALLY process a SACK. |
1111 | * | |
1112 | * Process the SACK against the outqueue. Mostly, this just frees | |
1113 | * things off the transmitted queue. | |
1114 | */ | |
1115 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) | |
1116 | { | |
1117 | struct sctp_association *asoc = q->asoc; | |
1118 | struct sctp_transport *transport; | |
1119 | struct sctp_chunk *tchunk = NULL; | |
9dbc15f0 | 1120 | struct list_head *lchunk, *transport_list, *temp; |
1da177e4 LT |
1121 | sctp_sack_variable_t *frags = sack->variable; |
1122 | __u32 sack_ctsn, ctsn, tsn; | |
1123 | __u32 highest_tsn, highest_new_tsn; | |
1124 | __u32 sack_a_rwnd; | |
1125 | unsigned outstanding; | |
1126 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1127 | int count_of_newacks = 0; | |
2cd9b822 | 1128 | int gap_ack_blocks; |
ea862c8d | 1129 | u8 accum_moved = 0; |
1da177e4 LT |
1130 | |
1131 | /* Grab the association's destination address list. */ | |
1132 | transport_list = &asoc->peer.transport_addr_list; | |
1133 | ||
1134 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
2cd9b822 | 1135 | gap_ack_blocks = ntohs(sack->num_gap_ack_blocks); |
1da177e4 LT |
1136 | /* |
1137 | * SFR-CACC algorithm: | |
1138 | * On receipt of a SACK the sender SHOULD execute the | |
1139 | * following statements. | |
1140 | * | |
1141 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1142 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1143 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1144 | * all destinations. | |
1da177e4 LT |
1145 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
1146 | * is set the receiver of the SACK MUST take the following actions: | |
1147 | * | |
1148 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1149 | * addresses. | |
ab5216a5 VY |
1150 | * |
1151 | * Only bother if changeover_active is set. Otherwise, this is | |
1152 | * totally suboptimal to do on every SACK. | |
1da177e4 | 1153 | */ |
ab5216a5 VY |
1154 | if (primary->cacc.changeover_active) { |
1155 | u8 clear_cycling = 0; | |
1156 | ||
1157 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1158 | primary->cacc.changeover_active = 0; | |
1159 | clear_cycling = 1; | |
1160 | } | |
1161 | ||
1162 | if (clear_cycling || gap_ack_blocks) { | |
1163 | list_for_each_entry(transport, transport_list, | |
1164 | transports) { | |
1165 | if (clear_cycling) | |
1166 | transport->cacc.cycling_changeover = 0; | |
1167 | if (gap_ack_blocks) | |
1168 | transport->cacc.cacc_saw_newack = 0; | |
1169 | } | |
1da177e4 LT |
1170 | } |
1171 | } | |
1172 | ||
1173 | /* Get the highest TSN in the sack. */ | |
1174 | highest_tsn = sack_ctsn; | |
2cd9b822 VY |
1175 | if (gap_ack_blocks) |
1176 | highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); | |
1da177e4 | 1177 | |
bfa0d984 | 1178 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) |
1da177e4 | 1179 | asoc->highest_sacked = highest_tsn; |
1da177e4 | 1180 | |
bfa0d984 | 1181 | highest_new_tsn = sack_ctsn; |
2cd9b822 | 1182 | |
1da177e4 LT |
1183 | /* Run through the retransmit queue. Credit bytes received |
1184 | * and free those chunks that we can. | |
1185 | */ | |
bfa0d984 | 1186 | sctp_check_transmitted(q, &q->retransmit, NULL, sack, &highest_new_tsn); |
1da177e4 LT |
1187 | |
1188 | /* Run through the transmitted queue. | |
1189 | * Credit bytes received and free those chunks which we can. | |
1190 | * | |
1191 | * This is a MASSIVE candidate for optimization. | |
1192 | */ | |
9dbc15f0 | 1193 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 | 1194 | sctp_check_transmitted(q, &transport->transmitted, |
bfa0d984 | 1195 | transport, sack, &highest_new_tsn); |
1da177e4 LT |
1196 | /* |
1197 | * SFR-CACC algorithm: | |
1198 | * C) Let count_of_newacks be the number of | |
1199 | * destinations for which cacc_saw_newack is set. | |
1200 | */ | |
1201 | if (transport->cacc.cacc_saw_newack) | |
1202 | count_of_newacks ++; | |
1203 | } | |
1204 | ||
ea862c8d VY |
1205 | /* Move the Cumulative TSN Ack Point if appropriate. */ |
1206 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) { | |
1207 | asoc->ctsn_ack_point = sack_ctsn; | |
1208 | accum_moved = 1; | |
1209 | } | |
1210 | ||
2cd9b822 | 1211 | if (gap_ack_blocks) { |
ea862c8d VY |
1212 | |
1213 | if (asoc->fast_recovery && accum_moved) | |
1214 | highest_new_tsn = highest_tsn; | |
1215 | ||
2cd9b822 VY |
1216 | list_for_each_entry(transport, transport_list, transports) |
1217 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1218 | highest_new_tsn, count_of_newacks); | |
1da177e4 LT |
1219 | } |
1220 | ||
1da177e4 LT |
1221 | /* Update unack_data field in the assoc. */ |
1222 | sctp_sack_update_unack_data(asoc, sack); | |
1223 | ||
1224 | ctsn = asoc->ctsn_ack_point; | |
1225 | ||
1226 | /* Throw away stuff rotting on the sack queue. */ | |
1227 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1228 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1229 | transmitted_list); | |
1230 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
5f9646c3 VY |
1231 | if (TSN_lte(tsn, ctsn)) { |
1232 | list_del_init(&tchunk->transmitted_list); | |
1da177e4 | 1233 | sctp_chunk_free(tchunk); |
5f9646c3 | 1234 | } |
1da177e4 LT |
1235 | } |
1236 | ||
1237 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1238 | * number of bytes still outstanding after processing the | |
1239 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1240 | */ | |
1241 | ||
1242 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
1243 | outstanding = q->outstanding_bytes; | |
1244 | ||
1245 | if (outstanding < sack_a_rwnd) | |
1246 | sack_a_rwnd -= outstanding; | |
1247 | else | |
1248 | sack_a_rwnd = 0; | |
1249 | ||
1250 | asoc->peer.rwnd = sack_a_rwnd; | |
1251 | ||
1252 | sctp_generate_fwdtsn(q, sack_ctsn); | |
1253 | ||
1254 | SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n", | |
0dc47877 | 1255 | __func__, sack_ctsn); |
1da177e4 LT |
1256 | SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, " |
1257 | "%p is 0x%x. Adv peer ack point: 0x%x\n", | |
0dc47877 | 1258 | __func__, asoc, ctsn, asoc->adv_peer_ack_point); |
1da177e4 LT |
1259 | |
1260 | /* See if all chunks are acked. | |
1261 | * Make sure the empty queue handler will get run later. | |
1262 | */ | |
79af02c2 | 1263 | q->empty = (list_empty(&q->out_chunk_list) && |
79af02c2 | 1264 | list_empty(&q->retransmit)); |
1da177e4 LT |
1265 | if (!q->empty) |
1266 | goto finish; | |
1267 | ||
9dbc15f0 | 1268 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 LT |
1269 | q->empty = q->empty && list_empty(&transport->transmitted); |
1270 | if (!q->empty) | |
1271 | goto finish; | |
1272 | } | |
1273 | ||
1274 | SCTP_DEBUG_PRINTK("sack queue is empty.\n"); | |
1275 | finish: | |
1276 | return q->empty; | |
1277 | } | |
1278 | ||
1279 | /* Is the outqueue empty? */ | |
1280 | int sctp_outq_is_empty(const struct sctp_outq *q) | |
1281 | { | |
1282 | return q->empty; | |
1283 | } | |
1284 | ||
1285 | /******************************************************************** | |
1286 | * 2nd Level Abstractions | |
1287 | ********************************************************************/ | |
1288 | ||
1289 | /* Go through a transport's transmitted list or the association's retransmit | |
1290 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1291 | * The retransmit list will not have an associated transport. | |
1292 | * | |
1293 | * I added coherent debug information output. --xguo | |
1294 | * | |
1295 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1296 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1297 | * KEPT TSN6-TSN7, etc. | |
1298 | */ | |
1299 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1300 | struct list_head *transmitted_queue, | |
1301 | struct sctp_transport *transport, | |
1302 | struct sctp_sackhdr *sack, | |
bfa0d984 | 1303 | __u32 *highest_new_tsn_in_sack) |
1da177e4 LT |
1304 | { |
1305 | struct list_head *lchunk; | |
1306 | struct sctp_chunk *tchunk; | |
1307 | struct list_head tlist; | |
1308 | __u32 tsn; | |
1309 | __u32 sack_ctsn; | |
1310 | __u32 rtt; | |
1311 | __u8 restart_timer = 0; | |
1312 | int bytes_acked = 0; | |
31b02e15 | 1313 | int migrate_bytes = 0; |
1da177e4 LT |
1314 | |
1315 | /* These state variables are for coherent debug output. --xguo */ | |
1316 | ||
1317 | #if SCTP_DEBUG | |
1318 | __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */ | |
1319 | __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */ | |
1320 | __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */ | |
1321 | __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */ | |
1322 | ||
1323 | /* 0 : The last TSN was ACKed. | |
1324 | * 1 : The last TSN was NOT ACKed (i.e. KEPT). | |
1325 | * -1: We need to initialize. | |
1326 | */ | |
1327 | int dbg_prt_state = -1; | |
1328 | #endif /* SCTP_DEBUG */ | |
1329 | ||
1330 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
1331 | ||
1332 | INIT_LIST_HEAD(&tlist); | |
1333 | ||
1334 | /* The while loop will skip empty transmitted queues. */ | |
1335 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1336 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1337 | transmitted_list); | |
1338 | ||
1339 | if (sctp_chunk_abandoned(tchunk)) { | |
1340 | /* Move the chunk to abandoned list. */ | |
1341 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
1342 | |
1343 | /* If this chunk has not been acked, stop | |
1344 | * considering it as 'outstanding'. | |
1345 | */ | |
1346 | if (!tchunk->tsn_gap_acked) { | |
31b02e15 VY |
1347 | if (tchunk->transport) |
1348 | tchunk->transport->flight_size -= | |
1349 | sctp_data_size(tchunk); | |
8c4a2d41 VY |
1350 | q->outstanding_bytes -= sctp_data_size(tchunk); |
1351 | } | |
1da177e4 LT |
1352 | continue; |
1353 | } | |
1354 | ||
1355 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1356 | if (sctp_acked(sack, tsn)) { | |
1357 | /* If this queue is the retransmit queue, the | |
1358 | * retransmit timer has already reclaimed | |
1359 | * the outstanding bytes for this chunk, so only | |
1360 | * count bytes associated with a transport. | |
1361 | */ | |
1362 | if (transport) { | |
1363 | /* If this chunk is being used for RTT | |
1364 | * measurement, calculate the RTT and update | |
1365 | * the RTO using this value. | |
1366 | * | |
1367 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1368 | * MUST NOT be made using packets that were | |
1369 | * retransmitted (and thus for which it is | |
1370 | * ambiguous whether the reply was for the | |
1371 | * first instance of the packet or a later | |
1372 | * instance). | |
1373 | */ | |
d808ad9a | 1374 | if (!tchunk->tsn_gap_acked && |
1da177e4 | 1375 | tchunk->rtt_in_progress) { |
4c9f5d53 | 1376 | tchunk->rtt_in_progress = 0; |
1da177e4 LT |
1377 | rtt = jiffies - tchunk->sent_at; |
1378 | sctp_transport_update_rto(transport, | |
1379 | rtt); | |
1380 | } | |
1381 | } | |
31b02e15 VY |
1382 | |
1383 | /* If the chunk hasn't been marked as ACKED, | |
1384 | * mark it and account bytes_acked if the | |
1385 | * chunk had a valid transport (it will not | |
1386 | * have a transport if ASCONF had deleted it | |
1387 | * while DATA was outstanding). | |
1388 | */ | |
1389 | if (!tchunk->tsn_gap_acked) { | |
1390 | tchunk->tsn_gap_acked = 1; | |
bfa0d984 | 1391 | *highest_new_tsn_in_sack = tsn; |
31b02e15 VY |
1392 | bytes_acked += sctp_data_size(tchunk); |
1393 | if (!tchunk->transport) | |
1394 | migrate_bytes += sctp_data_size(tchunk); | |
1395 | } | |
1396 | ||
d808ad9a | 1397 | if (TSN_lte(tsn, sack_ctsn)) { |
1da177e4 LT |
1398 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
1399 | * | |
1400 | * R3) Whenever a SACK is received | |
1401 | * that acknowledges the DATA chunk | |
1402 | * with the earliest outstanding TSN | |
1403 | * for that address, restart T3-rtx | |
1404 | * timer for that address with its | |
1405 | * current RTO. | |
1406 | */ | |
1407 | restart_timer = 1; | |
1408 | ||
1409 | if (!tchunk->tsn_gap_acked) { | |
1da177e4 LT |
1410 | /* |
1411 | * SFR-CACC algorithm: | |
1412 | * 2) If the SACK contains gap acks | |
1413 | * and the flag CHANGEOVER_ACTIVE is | |
1414 | * set the receiver of the SACK MUST | |
1415 | * take the following action: | |
1416 | * | |
1417 | * B) For each TSN t being acked that | |
1418 | * has not been acked in any SACK so | |
1419 | * far, set cacc_saw_newack to 1 for | |
1420 | * the destination that the TSN was | |
1421 | * sent to. | |
1422 | */ | |
1423 | if (transport && | |
1424 | sack->num_gap_ack_blocks && | |
1425 | q->asoc->peer.primary_path->cacc. | |
1426 | changeover_active) | |
1427 | transport->cacc.cacc_saw_newack | |
1428 | = 1; | |
1429 | } | |
1430 | ||
1431 | list_add_tail(&tchunk->transmitted_list, | |
1432 | &q->sacked); | |
1433 | } else { | |
1434 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1435 | * M2) Each time a SACK arrives reporting | |
1436 | * 'Stray DATA chunk(s)' record the highest TSN | |
1437 | * reported as newly acknowledged, call this | |
1438 | * value 'HighestTSNinSack'. A newly | |
1439 | * acknowledged DATA chunk is one not | |
1440 | * previously acknowledged in a SACK. | |
1441 | * | |
1442 | * When the SCTP sender of data receives a SACK | |
1443 | * chunk that acknowledges, for the first time, | |
1444 | * the receipt of a DATA chunk, all the still | |
1445 | * unacknowledged DATA chunks whose TSN is | |
1446 | * older than that newly acknowledged DATA | |
1447 | * chunk, are qualified as 'Stray DATA chunks'. | |
1448 | */ | |
1da177e4 LT |
1449 | list_add_tail(lchunk, &tlist); |
1450 | } | |
1451 | ||
1452 | #if SCTP_DEBUG | |
1453 | switch (dbg_prt_state) { | |
1454 | case 0: /* last TSN was ACKed */ | |
1455 | if (dbg_last_ack_tsn + 1 == tsn) { | |
1456 | /* This TSN belongs to the | |
1457 | * current ACK range. | |
1458 | */ | |
1459 | break; | |
1460 | } | |
1461 | ||
1462 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
1463 | /* Display the end of the | |
1464 | * current range. | |
1465 | */ | |
145ce502 JP |
1466 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1467 | dbg_last_ack_tsn); | |
1da177e4 LT |
1468 | } |
1469 | ||
1470 | /* Start a new range. */ | |
145ce502 | 1471 | SCTP_DEBUG_PRINTK_CONT(",%08x", tsn); |
1da177e4 LT |
1472 | dbg_ack_tsn = tsn; |
1473 | break; | |
1474 | ||
1475 | case 1: /* The last TSN was NOT ACKed. */ | |
1476 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
1477 | /* Display the end of current range. */ | |
145ce502 JP |
1478 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1479 | dbg_last_kept_tsn); | |
1da177e4 LT |
1480 | } |
1481 | ||
145ce502 | 1482 | SCTP_DEBUG_PRINTK_CONT("\n"); |
1da177e4 LT |
1483 | |
1484 | /* FALL THROUGH... */ | |
1485 | default: | |
1486 | /* This is the first-ever TSN we examined. */ | |
1487 | /* Start a new range of ACK-ed TSNs. */ | |
1488 | SCTP_DEBUG_PRINTK("ACKed: %08x", tsn); | |
1489 | dbg_prt_state = 0; | |
1490 | dbg_ack_tsn = tsn; | |
3ff50b79 | 1491 | } |
1da177e4 LT |
1492 | |
1493 | dbg_last_ack_tsn = tsn; | |
1494 | #endif /* SCTP_DEBUG */ | |
1495 | ||
1496 | } else { | |
1497 | if (tchunk->tsn_gap_acked) { | |
1498 | SCTP_DEBUG_PRINTK("%s: Receiver reneged on " | |
1499 | "data TSN: 0x%x\n", | |
0dc47877 | 1500 | __func__, |
1da177e4 LT |
1501 | tsn); |
1502 | tchunk->tsn_gap_acked = 0; | |
1503 | ||
31b02e15 VY |
1504 | if (tchunk->transport) |
1505 | bytes_acked -= sctp_data_size(tchunk); | |
1da177e4 LT |
1506 | |
1507 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1508 | * | |
1509 | * R4) Whenever a SACK is received missing a | |
1510 | * TSN that was previously acknowledged via a | |
1511 | * Gap Ack Block, start T3-rtx for the | |
1512 | * destination address to which the DATA | |
1513 | * chunk was originally | |
1514 | * transmitted if it is not already running. | |
1515 | */ | |
1516 | restart_timer = 1; | |
1517 | } | |
1518 | ||
1519 | list_add_tail(lchunk, &tlist); | |
1520 | ||
1521 | #if SCTP_DEBUG | |
1522 | /* See the above comments on ACK-ed TSNs. */ | |
1523 | switch (dbg_prt_state) { | |
1524 | case 1: | |
1525 | if (dbg_last_kept_tsn + 1 == tsn) | |
1526 | break; | |
1527 | ||
1528 | if (dbg_last_kept_tsn != dbg_kept_tsn) | |
145ce502 JP |
1529 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1530 | dbg_last_kept_tsn); | |
1da177e4 | 1531 | |
145ce502 | 1532 | SCTP_DEBUG_PRINTK_CONT(",%08x", tsn); |
1da177e4 LT |
1533 | dbg_kept_tsn = tsn; |
1534 | break; | |
1535 | ||
1536 | case 0: | |
1537 | if (dbg_last_ack_tsn != dbg_ack_tsn) | |
145ce502 JP |
1538 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1539 | dbg_last_ack_tsn); | |
1540 | SCTP_DEBUG_PRINTK_CONT("\n"); | |
1da177e4 LT |
1541 | |
1542 | /* FALL THROUGH... */ | |
1543 | default: | |
1544 | SCTP_DEBUG_PRINTK("KEPT: %08x",tsn); | |
1545 | dbg_prt_state = 1; | |
1546 | dbg_kept_tsn = tsn; | |
3ff50b79 | 1547 | } |
1da177e4 LT |
1548 | |
1549 | dbg_last_kept_tsn = tsn; | |
1550 | #endif /* SCTP_DEBUG */ | |
1551 | } | |
1552 | } | |
1553 | ||
1554 | #if SCTP_DEBUG | |
1555 | /* Finish off the last range, displaying its ending TSN. */ | |
1556 | switch (dbg_prt_state) { | |
1557 | case 0: | |
1558 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
145ce502 | 1559 | SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_ack_tsn); |
1da177e4 | 1560 | } else { |
145ce502 | 1561 | SCTP_DEBUG_PRINTK_CONT("\n"); |
1da177e4 LT |
1562 | } |
1563 | break; | |
1564 | ||
1565 | case 1: | |
1566 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
145ce502 | 1567 | SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_kept_tsn); |
1da177e4 | 1568 | } else { |
145ce502 | 1569 | SCTP_DEBUG_PRINTK_CONT("\n"); |
1da177e4 | 1570 | } |
3ff50b79 | 1571 | } |
1da177e4 LT |
1572 | #endif /* SCTP_DEBUG */ |
1573 | if (transport) { | |
1574 | if (bytes_acked) { | |
31b02e15 VY |
1575 | /* We may have counted DATA that was migrated |
1576 | * to this transport due to DEL-IP operation. | |
1577 | * Subtract those bytes, since the were never | |
1578 | * send on this transport and shouldn't be | |
1579 | * credited to this transport. | |
1580 | */ | |
1581 | bytes_acked -= migrate_bytes; | |
1582 | ||
1da177e4 LT |
1583 | /* 8.2. When an outstanding TSN is acknowledged, |
1584 | * the endpoint shall clear the error counter of | |
1585 | * the destination transport address to which the | |
1586 | * DATA chunk was last sent. | |
1587 | * The association's overall error counter is | |
1588 | * also cleared. | |
1589 | */ | |
1590 | transport->error_count = 0; | |
1591 | transport->asoc->overall_error_count = 0; | |
1592 | ||
1593 | /* Mark the destination transport address as | |
1594 | * active if it is not so marked. | |
1595 | */ | |
ad8fec17 SS |
1596 | if ((transport->state == SCTP_INACTIVE) || |
1597 | (transport->state == SCTP_UNCONFIRMED)) { | |
1da177e4 LT |
1598 | sctp_assoc_control_transport( |
1599 | transport->asoc, | |
1600 | transport, | |
1601 | SCTP_TRANSPORT_UP, | |
1602 | SCTP_RECEIVED_SACK); | |
1603 | } | |
1604 | ||
1605 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1606 | bytes_acked); | |
1607 | ||
1608 | transport->flight_size -= bytes_acked; | |
8b73a07c GJ |
1609 | if (transport->flight_size == 0) |
1610 | transport->partial_bytes_acked = 0; | |
31b02e15 | 1611 | q->outstanding_bytes -= bytes_acked + migrate_bytes; |
1da177e4 LT |
1612 | } else { |
1613 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1614 | * When a sender is doing zero window probing, it | |
1615 | * should not timeout the association if it continues | |
1616 | * to receive new packets from the receiver. The | |
1617 | * reason is that the receiver MAY keep its window | |
1618 | * closed for an indefinite time. | |
1619 | * A sender is doing zero window probing when the | |
1620 | * receiver's advertised window is zero, and there is | |
1621 | * only one data chunk in flight to the receiver. | |
1622 | */ | |
1623 | if (!q->asoc->peer.rwnd && | |
1624 | !list_empty(&tlist) && | |
1625 | (sack_ctsn+2 == q->asoc->next_tsn)) { | |
1626 | SCTP_DEBUG_PRINTK("%s: SACK received for zero " | |
1627 | "window probe: %u\n", | |
0dc47877 | 1628 | __func__, sack_ctsn); |
1da177e4 LT |
1629 | q->asoc->overall_error_count = 0; |
1630 | transport->error_count = 0; | |
1631 | } | |
1632 | } | |
1633 | ||
1634 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1635 | * | |
1636 | * R2) Whenever all outstanding data sent to an address have | |
1637 | * been acknowledged, turn off the T3-rtx timer of that | |
1638 | * address. | |
1639 | */ | |
1640 | if (!transport->flight_size) { | |
1641 | if (timer_pending(&transport->T3_rtx_timer) && | |
1642 | del_timer(&transport->T3_rtx_timer)) { | |
1643 | sctp_transport_put(transport); | |
1644 | } | |
1645 | } else if (restart_timer) { | |
1646 | if (!mod_timer(&transport->T3_rtx_timer, | |
1647 | jiffies + transport->rto)) | |
1648 | sctp_transport_hold(transport); | |
1649 | } | |
1650 | } | |
1651 | ||
1652 | list_splice(&tlist, transmitted_queue); | |
1653 | } | |
1654 | ||
1655 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1656 | static void sctp_mark_missing(struct sctp_outq *q, | |
1657 | struct list_head *transmitted_queue, | |
1658 | struct sctp_transport *transport, | |
1659 | __u32 highest_new_tsn_in_sack, | |
1660 | int count_of_newacks) | |
1661 | { | |
1662 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1663 | __u32 tsn; |
1664 | char do_fast_retransmit = 0; | |
ea862c8d VY |
1665 | struct sctp_association *asoc = q->asoc; |
1666 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1da177e4 | 1667 | |
9dbc15f0 | 1668 | list_for_each_entry(chunk, transmitted_queue, transmitted_list) { |
1da177e4 | 1669 | |
1da177e4 LT |
1670 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1671 | ||
1672 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1673 | * 'Unacknowledged TSN's', if the TSN number of an | |
1674 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1675 | * value, increment the 'TSN.Missing.Report' count on that | |
1676 | * chunk if it has NOT been fast retransmitted or marked for | |
1677 | * fast retransmit already. | |
1678 | */ | |
c226ef9b | 1679 | if (chunk->fast_retransmit == SCTP_CAN_FRTX && |
1da177e4 LT |
1680 | !chunk->tsn_gap_acked && |
1681 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1682 | ||
1683 | /* SFR-CACC may require us to skip marking | |
1684 | * this chunk as missing. | |
1685 | */ | |
1686 | if (!transport || !sctp_cacc_skip(primary, transport, | |
1687 | count_of_newacks, tsn)) { | |
1688 | chunk->tsn_missing_report++; | |
1689 | ||
1690 | SCTP_DEBUG_PRINTK( | |
1691 | "%s: TSN 0x%x missing counter: %d\n", | |
0dc47877 | 1692 | __func__, tsn, |
1da177e4 LT |
1693 | chunk->tsn_missing_report); |
1694 | } | |
1695 | } | |
1696 | /* | |
1697 | * M4) If any DATA chunk is found to have a | |
1698 | * 'TSN.Missing.Report' | |
27852c26 | 1699 | * value larger than or equal to 3, mark that chunk for |
1da177e4 LT |
1700 | * retransmission and start the fast retransmit procedure. |
1701 | */ | |
1702 | ||
27852c26 | 1703 | if (chunk->tsn_missing_report >= 3) { |
c226ef9b | 1704 | chunk->fast_retransmit = SCTP_NEED_FRTX; |
1da177e4 LT |
1705 | do_fast_retransmit = 1; |
1706 | } | |
1707 | } | |
1708 | ||
1709 | if (transport) { | |
1710 | if (do_fast_retransmit) | |
1711 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1712 | ||
1713 | SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, " | |
1714 | "ssthresh: %d, flight_size: %d, pba: %d\n", | |
0dc47877 | 1715 | __func__, transport, transport->cwnd, |
d808ad9a | 1716 | transport->ssthresh, transport->flight_size, |
1da177e4 LT |
1717 | transport->partial_bytes_acked); |
1718 | } | |
1719 | } | |
1720 | ||
1721 | /* Is the given TSN acked by this packet? */ | |
1722 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1723 | { | |
1724 | int i; | |
1725 | sctp_sack_variable_t *frags; | |
1726 | __u16 gap; | |
1727 | __u32 ctsn = ntohl(sack->cum_tsn_ack); | |
1728 | ||
d808ad9a | 1729 | if (TSN_lte(tsn, ctsn)) |
1da177e4 LT |
1730 | goto pass; |
1731 | ||
1732 | /* 3.3.4 Selective Acknowledgement (SACK) (3): | |
1733 | * | |
1734 | * Gap Ack Blocks: | |
1735 | * These fields contain the Gap Ack Blocks. They are repeated | |
1736 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1737 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1738 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1739 | * Ack + Gap Ack Block Start) and less than or equal to | |
1740 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1741 | * Block are assumed to have been received correctly. | |
1742 | */ | |
1743 | ||
1744 | frags = sack->variable; | |
1745 | gap = tsn - ctsn; | |
1746 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { | |
1747 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && | |
1748 | TSN_lte(gap, ntohs(frags[i].gab.end))) | |
1749 | goto pass; | |
1750 | } | |
1751 | ||
1752 | return 0; | |
1753 | pass: | |
1754 | return 1; | |
1755 | } | |
1756 | ||
1757 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
9f81bcd9 | 1758 | int nskips, __be16 stream) |
1da177e4 LT |
1759 | { |
1760 | int i; | |
1761 | ||
1762 | for (i = 0; i < nskips; i++) { | |
1763 | if (skiplist[i].stream == stream) | |
1764 | return i; | |
1765 | } | |
1766 | return i; | |
1767 | } | |
1768 | ||
1769 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
1770 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) | |
1771 | { | |
1772 | struct sctp_association *asoc = q->asoc; | |
1773 | struct sctp_chunk *ftsn_chunk = NULL; | |
1774 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1775 | int nskips = 0; | |
1776 | int skip_pos = 0; | |
1777 | __u32 tsn; | |
1778 | struct sctp_chunk *chunk; | |
1779 | struct list_head *lchunk, *temp; | |
1780 | ||
76595024 WY |
1781 | if (!asoc->peer.prsctp_capable) |
1782 | return; | |
1783 | ||
1da177e4 LT |
1784 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
1785 | * received SACK. | |
d808ad9a | 1786 | * |
1da177e4 LT |
1787 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
1788 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1789 | */ | |
1790 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1791 | asoc->adv_peer_ack_point = ctsn; | |
1792 | ||
1793 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1794 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1795 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1796 | * shown in the following example: | |
1797 | * | |
1798 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1799 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
d808ad9a | 1800 | * |
1da177e4 LT |
1801 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
1802 | * normal SACK processing local advancement | |
1803 | * ... ... | |
1804 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1805 | * 103 abandoned 103 abandoned | |
1806 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1807 | * 105 105 | |
1808 | * 106 acked 106 acked | |
1809 | * ... ... | |
1810 | * | |
1811 | * In this example, the data sender successfully advanced the | |
1812 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1813 | */ | |
1814 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1815 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1816 | transmitted_list); | |
1817 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1818 | ||
1819 | /* Remove any chunks in the abandoned queue that are acked by | |
1820 | * the ctsn. | |
d808ad9a | 1821 | */ |
1da177e4 LT |
1822 | if (TSN_lte(tsn, ctsn)) { |
1823 | list_del_init(lchunk); | |
1da177e4 LT |
1824 | sctp_chunk_free(chunk); |
1825 | } else { | |
1826 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1827 | asoc->adv_peer_ack_point = tsn; | |
1828 | if (chunk->chunk_hdr->flags & | |
1829 | SCTP_DATA_UNORDERED) | |
1830 | continue; | |
1831 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1832 | nskips, | |
1833 | chunk->subh.data_hdr->stream); | |
1834 | ftsn_skip_arr[skip_pos].stream = | |
1835 | chunk->subh.data_hdr->stream; | |
1836 | ftsn_skip_arr[skip_pos].ssn = | |
1837 | chunk->subh.data_hdr->ssn; | |
1838 | if (skip_pos == nskips) | |
1839 | nskips++; | |
1840 | if (nskips == 10) | |
1841 | break; | |
1842 | } else | |
1843 | break; | |
1844 | } | |
1845 | } | |
1846 | ||
1847 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1848 | * is greater than the Cumulative TSN ACK carried in the received | |
1849 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1850 | * chunk containing the latest value of the | |
1851 | * "Advanced.Peer.Ack.Point". | |
1852 | * | |
1853 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1854 | * list each stream and sequence number in the forwarded TSN. This | |
1855 | * information will enable the receiver to easily find any | |
1856 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1857 | * SHOULD only be reported once; this means that if multiple | |
1858 | * abandoned messages occur in the same stream then only the | |
1859 | * highest abandoned stream sequence number is reported. If the | |
1860 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1861 | * the sender of the FORWARD TSN SHOULD lower the | |
1862 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1863 | * single MTU. | |
1864 | */ | |
1865 | if (asoc->adv_peer_ack_point > ctsn) | |
1866 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
d808ad9a | 1867 | nskips, &ftsn_skip_arr[0]); |
1da177e4 LT |
1868 | |
1869 | if (ftsn_chunk) { | |
79af02c2 | 1870 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
1da177e4 LT |
1871 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
1872 | } | |
1873 | } |