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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 | { | |
f246a7b7 VY |
134 | if (count_of_newacks < 2 && |
135 | (transport && !transport->cacc.cacc_saw_newack)) | |
1da177e4 LT |
136 | return 1; |
137 | return 0; | |
138 | } | |
139 | ||
140 | /* | |
141 | * SFR-CACC algorithm: | |
142 | * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD | |
143 | * execute steps C, D, F. | |
144 | * | |
145 | * C has been implemented in sctp_outq_sack | |
146 | */ | |
147 | static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, | |
148 | struct sctp_transport *transport, | |
149 | int count_of_newacks) | |
150 | { | |
151 | if (!primary->cacc.cycling_changeover) { | |
152 | if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks)) | |
153 | return 1; | |
154 | if (sctp_cacc_skip_3_1_f(transport, count_of_newacks)) | |
155 | return 1; | |
156 | return 0; | |
157 | } | |
158 | return 0; | |
159 | } | |
160 | ||
161 | /* | |
162 | * SFR-CACC algorithm: | |
163 | * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less | |
164 | * than next_tsn_at_change of the current primary, then | |
165 | * the sender MUST NOT increment missing report count | |
166 | * for t. | |
167 | */ | |
168 | static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) | |
169 | { | |
170 | if (primary->cacc.cycling_changeover && | |
171 | TSN_lt(tsn, primary->cacc.next_tsn_at_change)) | |
172 | return 1; | |
173 | return 0; | |
174 | } | |
175 | ||
176 | /* | |
177 | * SFR-CACC algorithm: | |
178 | * 3) If the missing report count for TSN t is to be | |
179 | * incremented according to [RFC2960] and | |
180 | * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, | |
25985edc | 181 | * then the sender MUST further execute steps 3.1 and |
1da177e4 LT |
182 | * 3.2 to determine if the missing report count for |
183 | * TSN t SHOULD NOT be incremented. | |
184 | * | |
185 | * 3.3) If 3.1 and 3.2 do not dictate that the missing | |
186 | * report count for t should not be incremented, then | |
25985edc | 187 | * the sender SHOULD increment missing report count for |
1da177e4 LT |
188 | * t (according to [RFC2960] and [SCTP_STEWART_2002]). |
189 | */ | |
190 | static inline int sctp_cacc_skip(struct sctp_transport *primary, | |
191 | struct sctp_transport *transport, | |
192 | int count_of_newacks, | |
193 | __u32 tsn) | |
194 | { | |
195 | if (primary->cacc.changeover_active && | |
f64f9e71 JP |
196 | (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) || |
197 | sctp_cacc_skip_3_2(primary, tsn))) | |
1da177e4 LT |
198 | return 1; |
199 | return 0; | |
200 | } | |
201 | ||
202 | /* Initialize an existing sctp_outq. This does the boring stuff. | |
203 | * You still need to define handlers if you really want to DO | |
204 | * something with this structure... | |
205 | */ | |
206 | void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) | |
207 | { | |
208 | q->asoc = asoc; | |
79af02c2 DM |
209 | INIT_LIST_HEAD(&q->out_chunk_list); |
210 | INIT_LIST_HEAD(&q->control_chunk_list); | |
1da177e4 LT |
211 | INIT_LIST_HEAD(&q->retransmit); |
212 | INIT_LIST_HEAD(&q->sacked); | |
213 | INIT_LIST_HEAD(&q->abandoned); | |
214 | ||
62aeaff5 | 215 | q->fast_rtx = 0; |
1da177e4 LT |
216 | q->outstanding_bytes = 0; |
217 | q->empty = 1; | |
218 | q->cork = 0; | |
219 | ||
220 | q->malloced = 0; | |
221 | q->out_qlen = 0; | |
222 | } | |
223 | ||
224 | /* Free the outqueue structure and any related pending chunks. | |
225 | */ | |
226 | void sctp_outq_teardown(struct sctp_outq *q) | |
227 | { | |
228 | struct sctp_transport *transport; | |
9dbc15f0 | 229 | struct list_head *lchunk, *temp; |
79af02c2 | 230 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
231 | |
232 | /* Throw away unacknowledged chunks. */ | |
9dbc15f0 RD |
233 | list_for_each_entry(transport, &q->asoc->peer.transport_addr_list, |
234 | transports) { | |
1da177e4 LT |
235 | while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) { |
236 | chunk = list_entry(lchunk, struct sctp_chunk, | |
237 | transmitted_list); | |
238 | /* Mark as part of a failed message. */ | |
239 | sctp_chunk_fail(chunk, q->error); | |
240 | sctp_chunk_free(chunk); | |
241 | } | |
242 | } | |
243 | ||
244 | /* Throw away chunks that have been gap ACKed. */ | |
245 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
246 | list_del_init(lchunk); | |
247 | chunk = list_entry(lchunk, struct sctp_chunk, | |
248 | transmitted_list); | |
249 | sctp_chunk_fail(chunk, q->error); | |
250 | sctp_chunk_free(chunk); | |
251 | } | |
252 | ||
253 | /* Throw away any chunks in the retransmit queue. */ | |
254 | list_for_each_safe(lchunk, temp, &q->retransmit) { | |
255 | list_del_init(lchunk); | |
256 | chunk = list_entry(lchunk, struct sctp_chunk, | |
257 | transmitted_list); | |
258 | sctp_chunk_fail(chunk, q->error); | |
259 | sctp_chunk_free(chunk); | |
260 | } | |
261 | ||
262 | /* Throw away any chunks that are in the abandoned queue. */ | |
263 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
264 | list_del_init(lchunk); | |
265 | chunk = list_entry(lchunk, struct sctp_chunk, | |
266 | transmitted_list); | |
267 | sctp_chunk_fail(chunk, q->error); | |
268 | sctp_chunk_free(chunk); | |
269 | } | |
270 | ||
271 | /* Throw away any leftover data chunks. */ | |
272 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { | |
273 | ||
274 | /* Mark as send failure. */ | |
275 | sctp_chunk_fail(chunk, q->error); | |
276 | sctp_chunk_free(chunk); | |
277 | } | |
278 | ||
279 | q->error = 0; | |
280 | ||
281 | /* Throw away any leftover control chunks. */ | |
79af02c2 DM |
282 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
283 | list_del_init(&chunk->list); | |
1da177e4 | 284 | sctp_chunk_free(chunk); |
79af02c2 | 285 | } |
1da177e4 LT |
286 | } |
287 | ||
288 | /* Free the outqueue structure and any related pending chunks. */ | |
289 | void sctp_outq_free(struct sctp_outq *q) | |
290 | { | |
291 | /* Throw away leftover chunks. */ | |
292 | sctp_outq_teardown(q); | |
293 | ||
294 | /* If we were kmalloc()'d, free the memory. */ | |
295 | if (q->malloced) | |
296 | kfree(q); | |
297 | } | |
298 | ||
299 | /* Put a new chunk in an sctp_outq. */ | |
300 | int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) | |
301 | { | |
302 | int error = 0; | |
303 | ||
304 | SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n", | |
305 | q, chunk, chunk && chunk->chunk_hdr ? | |
306 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) | |
307 | : "Illegal Chunk"); | |
308 | ||
309 | /* If it is data, queue it up, otherwise, send it | |
310 | * immediately. | |
311 | */ | |
ec7b9519 | 312 | if (sctp_chunk_is_data(chunk)) { |
1da177e4 LT |
313 | /* Is it OK to queue data chunks? */ |
314 | /* From 9. Termination of Association | |
315 | * | |
316 | * When either endpoint performs a shutdown, the | |
317 | * association on each peer will stop accepting new | |
318 | * data from its user and only deliver data in queue | |
319 | * at the time of sending or receiving the SHUTDOWN | |
320 | * chunk. | |
321 | */ | |
322 | switch (q->asoc->state) { | |
1da177e4 LT |
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 | 413 | q->outstanding_bytes -= sctp_data_size(chunk); |
a76c0adf | 414 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
8c4a2d41 | 415 | } |
1da177e4 LT |
416 | continue; |
417 | } | |
418 | ||
b6157d8e VY |
419 | /* If we are doing retransmission due to a timeout or pmtu |
420 | * discovery, only the chunks that are not yet acked should | |
421 | * be added to the retransmit queue. | |
1da177e4 | 422 | */ |
b6157d8e | 423 | if ((reason == SCTP_RTXR_FAST_RTX && |
c226ef9b | 424 | (chunk->fast_retransmit == SCTP_NEED_FRTX)) || |
b6157d8e | 425 | (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) { |
1da177e4 LT |
426 | /* RFC 2960 6.2.1 Processing a Received SACK |
427 | * | |
428 | * C) Any time a DATA chunk is marked for | |
429 | * retransmission (via either T3-rtx timer expiration | |
430 | * (Section 6.3.3) or via fast retransmit | |
431 | * (Section 7.2.4)), add the data size of those | |
432 | * chunks to the rwnd. | |
433 | */ | |
a76c0adf | 434 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
1da177e4 | 435 | q->outstanding_bytes -= sctp_data_size(chunk); |
31b02e15 VY |
436 | if (chunk->transport) |
437 | transport->flight_size -= sctp_data_size(chunk); | |
1da177e4 LT |
438 | |
439 | /* sctpimpguide-05 Section 2.8.2 | |
440 | * M5) If a T3-rtx timer expires, the | |
441 | * 'TSN.Missing.Report' of all affected TSNs is set | |
442 | * to 0. | |
443 | */ | |
444 | chunk->tsn_missing_report = 0; | |
445 | ||
446 | /* If a chunk that is being used for RTT measurement | |
447 | * has to be retransmitted, we cannot use this chunk | |
448 | * anymore for RTT measurements. Reset rto_pending so | |
449 | * that a new RTT measurement is started when a new | |
450 | * data chunk is sent. | |
451 | */ | |
452 | if (chunk->rtt_in_progress) { | |
453 | chunk->rtt_in_progress = 0; | |
454 | transport->rto_pending = 0; | |
455 | } | |
456 | ||
457 | /* Move the chunk to the retransmit queue. The chunks | |
458 | * on the retransmit queue are always kept in order. | |
459 | */ | |
460 | list_del_init(lchunk); | |
461 | sctp_insert_list(&q->retransmit, lchunk); | |
462 | } | |
463 | } | |
464 | ||
b6157d8e | 465 | SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, " |
1da177e4 | 466 | "cwnd: %d, ssthresh: %d, flight_size: %d, " |
0dc47877 | 467 | "pba: %d\n", __func__, |
b6157d8e | 468 | transport, reason, |
1da177e4 LT |
469 | transport->cwnd, transport->ssthresh, |
470 | transport->flight_size, | |
471 | transport->partial_bytes_acked); | |
472 | ||
473 | } | |
474 | ||
475 | /* Mark all the eligible packets on a transport for retransmission and force | |
476 | * one packet out. | |
477 | */ | |
478 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, | |
479 | sctp_retransmit_reason_t reason) | |
480 | { | |
481 | int error = 0; | |
1da177e4 LT |
482 | |
483 | switch(reason) { | |
484 | case SCTP_RTXR_T3_RTX: | |
ac0b0462 | 485 | SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS); |
1da177e4 LT |
486 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); |
487 | /* Update the retran path if the T3-rtx timer has expired for | |
488 | * the current retran path. | |
489 | */ | |
490 | if (transport == transport->asoc->peer.retran_path) | |
491 | sctp_assoc_update_retran_path(transport->asoc); | |
58fbbed4 NH |
492 | transport->asoc->rtx_data_chunks += |
493 | transport->asoc->unack_data; | |
1da177e4 LT |
494 | break; |
495 | case SCTP_RTXR_FAST_RTX: | |
ac0b0462 | 496 | SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS); |
1da177e4 | 497 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); |
62aeaff5 | 498 | q->fast_rtx = 1; |
1da177e4 LT |
499 | break; |
500 | case SCTP_RTXR_PMTUD: | |
ac0b0462 | 501 | SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS); |
1da177e4 | 502 | break; |
b6157d8e VY |
503 | case SCTP_RTXR_T1_RTX: |
504 | SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS); | |
58fbbed4 | 505 | transport->asoc->init_retries++; |
b6157d8e | 506 | break; |
ac0b0462 SS |
507 | default: |
508 | BUG(); | |
1da177e4 LT |
509 | } |
510 | ||
b6157d8e | 511 | sctp_retransmit_mark(q, transport, reason); |
1da177e4 LT |
512 | |
513 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, | |
514 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by | |
515 | * following the procedures outlined in C1 - C5. | |
516 | */ | |
8b750ce5 VY |
517 | if (reason == SCTP_RTXR_T3_RTX) |
518 | sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); | |
1da177e4 | 519 | |
8b750ce5 VY |
520 | /* Flush the queues only on timeout, since fast_rtx is only |
521 | * triggered during sack processing and the queue | |
522 | * will be flushed at the end. | |
523 | */ | |
524 | if (reason != SCTP_RTXR_FAST_RTX) | |
525 | error = sctp_outq_flush(q, /* rtx_timeout */ 1); | |
1da177e4 LT |
526 | |
527 | if (error) | |
528 | q->asoc->base.sk->sk_err = -error; | |
529 | } | |
530 | ||
531 | /* | |
532 | * Transmit DATA chunks on the retransmit queue. Upon return from | |
533 | * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which | |
534 | * need to be transmitted by the caller. | |
535 | * We assume that pkt->transport has already been set. | |
536 | * | |
537 | * The return value is a normal kernel error return value. | |
538 | */ | |
539 | static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, | |
540 | int rtx_timeout, int *start_timer) | |
541 | { | |
542 | struct list_head *lqueue; | |
1da177e4 LT |
543 | struct sctp_transport *transport = pkt->transport; |
544 | sctp_xmit_t status; | |
545 | struct sctp_chunk *chunk, *chunk1; | |
62aeaff5 | 546 | int fast_rtx; |
1da177e4 | 547 | int error = 0; |
62aeaff5 | 548 | int timer = 0; |
8b750ce5 | 549 | int done = 0; |
1da177e4 | 550 | |
1da177e4 | 551 | lqueue = &q->retransmit; |
62aeaff5 | 552 | fast_rtx = q->fast_rtx; |
1da177e4 | 553 | |
8b750ce5 VY |
554 | /* This loop handles time-out retransmissions, fast retransmissions, |
555 | * and retransmissions due to opening of whindow. | |
556 | * | |
557 | * RFC 2960 6.3.3 Handle T3-rtx Expiration | |
1da177e4 LT |
558 | * |
559 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
560 | * outstanding DATA chunks for the address for which the | |
561 | * T3-rtx has expired will fit into a single packet, subject | |
562 | * to the MTU constraint for the path corresponding to the | |
563 | * destination transport address to which the retransmission | |
564 | * is being sent (this may be different from the address for | |
565 | * which the timer expires [see Section 6.4]). Call this value | |
566 | * K. Bundle and retransmit those K DATA chunks in a single | |
567 | * packet to the destination endpoint. | |
568 | * | |
569 | * [Just to be painfully clear, if we are retransmitting | |
570 | * because a timeout just happened, we should send only ONE | |
571 | * packet of retransmitted data.] | |
8b750ce5 VY |
572 | * |
573 | * For fast retransmissions we also send only ONE packet. However, | |
574 | * if we are just flushing the queue due to open window, we'll | |
575 | * try to send as much as possible. | |
1da177e4 | 576 | */ |
8b750ce5 | 577 | list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { |
4c6a6f42 WY |
578 | /* If the chunk is abandoned, move it to abandoned list. */ |
579 | if (sctp_chunk_abandoned(chunk)) { | |
580 | list_del_init(&chunk->transmitted_list); | |
581 | sctp_insert_list(&q->abandoned, | |
582 | &chunk->transmitted_list); | |
583 | continue; | |
584 | } | |
1da177e4 LT |
585 | |
586 | /* Make sure that Gap Acked TSNs are not retransmitted. A | |
587 | * simple approach is just to move such TSNs out of the | |
588 | * way and into a 'transmitted' queue and skip to the | |
589 | * next chunk. | |
590 | */ | |
591 | if (chunk->tsn_gap_acked) { | |
8b750ce5 VY |
592 | list_del(&chunk->transmitted_list); |
593 | list_add_tail(&chunk->transmitted_list, | |
594 | &transport->transmitted); | |
1da177e4 LT |
595 | continue; |
596 | } | |
597 | ||
8b750ce5 VY |
598 | /* If we are doing fast retransmit, ignore non-fast_rtransmit |
599 | * chunks | |
600 | */ | |
601 | if (fast_rtx && !chunk->fast_retransmit) | |
602 | continue; | |
603 | ||
bc4f841a | 604 | redo: |
1da177e4 LT |
605 | /* Attempt to append this chunk to the packet. */ |
606 | status = sctp_packet_append_chunk(pkt, chunk); | |
607 | ||
608 | switch (status) { | |
609 | case SCTP_XMIT_PMTU_FULL: | |
bc4f841a WY |
610 | if (!pkt->has_data && !pkt->has_cookie_echo) { |
611 | /* If this packet did not contain DATA then | |
612 | * retransmission did not happen, so do it | |
613 | * again. We'll ignore the error here since | |
614 | * control chunks are already freed so there | |
615 | * is nothing we can do. | |
616 | */ | |
617 | sctp_packet_transmit(pkt); | |
618 | goto redo; | |
619 | } | |
620 | ||
1da177e4 | 621 | /* Send this packet. */ |
62aeaff5 | 622 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
623 | |
624 | /* If we are retransmitting, we should only | |
625 | * send a single packet. | |
f246a7b7 | 626 | * Otherwise, try appending this chunk again. |
1da177e4 | 627 | */ |
8b750ce5 VY |
628 | if (rtx_timeout || fast_rtx) |
629 | done = 1; | |
f246a7b7 VY |
630 | else |
631 | goto redo; | |
1da177e4 | 632 | |
8b750ce5 | 633 | /* Bundle next chunk in the next round. */ |
1da177e4 LT |
634 | break; |
635 | ||
636 | case SCTP_XMIT_RWND_FULL: | |
d808ad9a | 637 | /* Send this packet. */ |
62aeaff5 | 638 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
639 | |
640 | /* Stop sending DATA as there is no more room | |
641 | * at the receiver. | |
642 | */ | |
8b750ce5 | 643 | done = 1; |
1da177e4 LT |
644 | break; |
645 | ||
646 | case SCTP_XMIT_NAGLE_DELAY: | |
d808ad9a | 647 | /* Send this packet. */ |
62aeaff5 | 648 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
649 | |
650 | /* Stop sending DATA because of nagle delay. */ | |
8b750ce5 | 651 | done = 1; |
1da177e4 LT |
652 | break; |
653 | ||
654 | default: | |
655 | /* The append was successful, so add this chunk to | |
656 | * the transmitted list. | |
657 | */ | |
8b750ce5 VY |
658 | list_del(&chunk->transmitted_list); |
659 | list_add_tail(&chunk->transmitted_list, | |
660 | &transport->transmitted); | |
1da177e4 | 661 | |
d808ad9a | 662 | /* Mark the chunk as ineligible for fast retransmit |
1da177e4 LT |
663 | * after it is retransmitted. |
664 | */ | |
c226ef9b NH |
665 | if (chunk->fast_retransmit == SCTP_NEED_FRTX) |
666 | chunk->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 | 667 | |
1da177e4 | 668 | q->empty = 0; |
1da177e4 | 669 | break; |
3ff50b79 | 670 | } |
1da177e4 | 671 | |
62aeaff5 VY |
672 | /* Set the timer if there were no errors */ |
673 | if (!error && !timer) | |
674 | timer = 1; | |
675 | ||
8b750ce5 VY |
676 | if (done) |
677 | break; | |
678 | } | |
679 | ||
680 | /* If we are here due to a retransmit timeout or a fast | |
681 | * retransmit and if there are any chunks left in the retransmit | |
682 | * queue that could not fit in the PMTU sized packet, they need | |
683 | * to be marked as ineligible for a subsequent fast retransmit. | |
684 | */ | |
685 | if (rtx_timeout || fast_rtx) { | |
686 | list_for_each_entry(chunk1, lqueue, transmitted_list) { | |
c226ef9b NH |
687 | if (chunk1->fast_retransmit == SCTP_NEED_FRTX) |
688 | chunk1->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 LT |
689 | } |
690 | } | |
691 | ||
62aeaff5 VY |
692 | *start_timer = timer; |
693 | ||
694 | /* Clear fast retransmit hint */ | |
695 | if (fast_rtx) | |
696 | q->fast_rtx = 0; | |
697 | ||
1da177e4 LT |
698 | return error; |
699 | } | |
700 | ||
701 | /* Cork the outqueue so queued chunks are really queued. */ | |
702 | int sctp_outq_uncork(struct sctp_outq *q) | |
703 | { | |
704 | int error = 0; | |
7d54dc68 | 705 | if (q->cork) |
1da177e4 | 706 | q->cork = 0; |
7d54dc68 | 707 | error = sctp_outq_flush(q, 0); |
1da177e4 LT |
708 | return error; |
709 | } | |
710 | ||
2e3216cd | 711 | |
1da177e4 LT |
712 | /* |
713 | * Try to flush an outqueue. | |
714 | * | |
715 | * Description: Send everything in q which we legally can, subject to | |
716 | * congestion limitations. | |
717 | * * Note: This function can be called from multiple contexts so appropriate | |
718 | * locking concerns must be made. Today we use the sock lock to protect | |
719 | * this function. | |
720 | */ | |
abd0b198 | 721 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) |
1da177e4 LT |
722 | { |
723 | struct sctp_packet *packet; | |
724 | struct sctp_packet singleton; | |
725 | struct sctp_association *asoc = q->asoc; | |
726 | __u16 sport = asoc->base.bind_addr.port; | |
727 | __u16 dport = asoc->peer.port; | |
728 | __u32 vtag = asoc->peer.i.init_tag; | |
1da177e4 LT |
729 | struct sctp_transport *transport = NULL; |
730 | struct sctp_transport *new_transport; | |
79af02c2 | 731 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
732 | sctp_xmit_t status; |
733 | int error = 0; | |
734 | int start_timer = 0; | |
2e3216cd | 735 | int one_packet = 0; |
1da177e4 LT |
736 | |
737 | /* These transports have chunks to send. */ | |
738 | struct list_head transport_list; | |
739 | struct list_head *ltransport; | |
740 | ||
741 | INIT_LIST_HEAD(&transport_list); | |
742 | packet = NULL; | |
743 | ||
744 | /* | |
745 | * 6.10 Bundling | |
746 | * ... | |
747 | * When bundling control chunks with DATA chunks, an | |
748 | * endpoint MUST place control chunks first in the outbound | |
749 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
750 | * within a SCTP packet in increasing order of TSN. | |
751 | * ... | |
752 | */ | |
753 | ||
79af02c2 | 754 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
8a07eb0a MH |
755 | /* RFC 5061, 5.3 |
756 | * F1) This means that until such time as the ASCONF | |
757 | * containing the add is acknowledged, the sender MUST | |
758 | * NOT use the new IP address as a source for ANY SCTP | |
759 | * packet except on carrying an ASCONF Chunk. | |
760 | */ | |
761 | if (asoc->src_out_of_asoc_ok && | |
762 | chunk->chunk_hdr->type != SCTP_CID_ASCONF) | |
763 | continue; | |
764 | ||
79af02c2 DM |
765 | list_del_init(&chunk->list); |
766 | ||
1da177e4 LT |
767 | /* Pick the right transport to use. */ |
768 | new_transport = chunk->transport; | |
769 | ||
770 | if (!new_transport) { | |
a08de64d VY |
771 | /* |
772 | * If we have a prior transport pointer, see if | |
773 | * the destination address of the chunk | |
774 | * matches the destination address of the | |
775 | * current transport. If not a match, then | |
776 | * try to look up the transport with a given | |
777 | * destination address. We do this because | |
778 | * after processing ASCONFs, we may have new | |
779 | * transports created. | |
780 | */ | |
781 | if (transport && | |
782 | sctp_cmp_addr_exact(&chunk->dest, | |
783 | &transport->ipaddr)) | |
784 | new_transport = transport; | |
785 | else | |
786 | new_transport = sctp_assoc_lookup_paddr(asoc, | |
787 | &chunk->dest); | |
788 | ||
789 | /* if we still don't have a new transport, then | |
790 | * use the current active path. | |
791 | */ | |
792 | if (!new_transport) | |
793 | new_transport = asoc->peer.active_path; | |
ad8fec17 SS |
794 | } else if ((new_transport->state == SCTP_INACTIVE) || |
795 | (new_transport->state == SCTP_UNCONFIRMED)) { | |
3f7a87d2 FF |
796 | /* If the chunk is Heartbeat or Heartbeat Ack, |
797 | * send it to chunk->transport, even if it's | |
1da177e4 LT |
798 | * inactive. |
799 | * | |
800 | * 3.3.6 Heartbeat Acknowledgement: | |
d808ad9a | 801 | * ... |
1da177e4 LT |
802 | * A HEARTBEAT ACK is always sent to the source IP |
803 | * address of the IP datagram containing the | |
804 | * HEARTBEAT chunk to which this ack is responding. | |
d808ad9a | 805 | * ... |
a08de64d VY |
806 | * |
807 | * ASCONF_ACKs also must be sent to the source. | |
1da177e4 LT |
808 | */ |
809 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && | |
a08de64d VY |
810 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK && |
811 | chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK) | |
1da177e4 LT |
812 | new_transport = asoc->peer.active_path; |
813 | } | |
814 | ||
815 | /* Are we switching transports? | |
816 | * Take care of transport locks. | |
817 | */ | |
818 | if (new_transport != transport) { | |
819 | transport = new_transport; | |
820 | if (list_empty(&transport->send_ready)) { | |
821 | list_add_tail(&transport->send_ready, | |
822 | &transport_list); | |
823 | } | |
824 | packet = &transport->packet; | |
825 | sctp_packet_config(packet, vtag, | |
826 | asoc->peer.ecn_capable); | |
827 | } | |
828 | ||
829 | switch (chunk->chunk_hdr->type) { | |
830 | /* | |
831 | * 6.10 Bundling | |
832 | * ... | |
833 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
834 | * COMPLETE with any other chunks. [Send them immediately.] | |
835 | */ | |
836 | case SCTP_CID_INIT: | |
837 | case SCTP_CID_INIT_ACK: | |
838 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
839 | sctp_packet_init(&singleton, transport, sport, dport); | |
840 | sctp_packet_config(&singleton, vtag, 0); | |
841 | sctp_packet_append_chunk(&singleton, chunk); | |
842 | error = sctp_packet_transmit(&singleton); | |
843 | if (error < 0) | |
844 | return error; | |
845 | break; | |
846 | ||
847 | case SCTP_CID_ABORT: | |
f4ad85ca GJ |
848 | if (sctp_test_T_bit(chunk)) { |
849 | packet->vtag = asoc->c.my_vtag; | |
850 | } | |
2e3216cd VY |
851 | /* The following chunks are "response" chunks, i.e. |
852 | * they are generated in response to something we | |
853 | * received. If we are sending these, then we can | |
854 | * send only 1 packet containing these chunks. | |
855 | */ | |
1da177e4 | 856 | case SCTP_CID_HEARTBEAT_ACK: |
1da177e4 | 857 | case SCTP_CID_SHUTDOWN_ACK: |
1da177e4 | 858 | case SCTP_CID_COOKIE_ACK: |
2e3216cd VY |
859 | case SCTP_CID_COOKIE_ECHO: |
860 | case SCTP_CID_ERROR: | |
1da177e4 | 861 | case SCTP_CID_ECN_CWR: |
1da177e4 | 862 | case SCTP_CID_ASCONF_ACK: |
2e3216cd | 863 | one_packet = 1; |
25985edc | 864 | /* Fall through */ |
2e3216cd VY |
865 | |
866 | case SCTP_CID_SACK: | |
867 | case SCTP_CID_HEARTBEAT: | |
868 | case SCTP_CID_SHUTDOWN: | |
869 | case SCTP_CID_ECN_ECNE: | |
870 | case SCTP_CID_ASCONF: | |
1da177e4 | 871 | case SCTP_CID_FWD_TSN: |
2e3216cd VY |
872 | status = sctp_packet_transmit_chunk(packet, chunk, |
873 | one_packet); | |
874 | if (status != SCTP_XMIT_OK) { | |
875 | /* put the chunk back */ | |
876 | list_add(&chunk->list, &q->control_chunk_list); | |
bd69b981 WY |
877 | } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) { |
878 | /* PR-SCTP C5) If a FORWARD TSN is sent, the | |
879 | * sender MUST assure that at least one T3-rtx | |
880 | * timer is running. | |
881 | */ | |
d9efc223 | 882 | sctp_transport_reset_timers(transport); |
2e3216cd | 883 | } |
1da177e4 LT |
884 | break; |
885 | ||
886 | default: | |
887 | /* We built a chunk with an illegal type! */ | |
888 | BUG(); | |
3ff50b79 | 889 | } |
1da177e4 LT |
890 | } |
891 | ||
8a07eb0a MH |
892 | if (q->asoc->src_out_of_asoc_ok) |
893 | goto sctp_flush_out; | |
894 | ||
1da177e4 LT |
895 | /* Is it OK to send data chunks? */ |
896 | switch (asoc->state) { | |
897 | case SCTP_STATE_COOKIE_ECHOED: | |
898 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
899 | * chunk. | |
900 | */ | |
901 | if (!packet || !packet->has_cookie_echo) | |
902 | break; | |
903 | ||
904 | /* fallthru */ | |
905 | case SCTP_STATE_ESTABLISHED: | |
906 | case SCTP_STATE_SHUTDOWN_PENDING: | |
907 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
908 | /* | |
909 | * RFC 2960 6.1 Transmission of DATA Chunks | |
910 | * | |
911 | * C) When the time comes for the sender to transmit, | |
912 | * before sending new DATA chunks, the sender MUST | |
913 | * first transmit any outstanding DATA chunks which | |
914 | * are marked for retransmission (limited by the | |
915 | * current cwnd). | |
916 | */ | |
917 | if (!list_empty(&q->retransmit)) { | |
f207c050 MH |
918 | if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED) |
919 | goto sctp_flush_out; | |
1da177e4 LT |
920 | if (transport == asoc->peer.retran_path) |
921 | goto retran; | |
922 | ||
923 | /* Switch transports & prepare the packet. */ | |
924 | ||
925 | transport = asoc->peer.retran_path; | |
926 | ||
927 | if (list_empty(&transport->send_ready)) { | |
928 | list_add_tail(&transport->send_ready, | |
929 | &transport_list); | |
930 | } | |
931 | ||
932 | packet = &transport->packet; | |
933 | sctp_packet_config(packet, vtag, | |
934 | asoc->peer.ecn_capable); | |
935 | retran: | |
936 | error = sctp_outq_flush_rtx(q, packet, | |
937 | rtx_timeout, &start_timer); | |
938 | ||
939 | if (start_timer) | |
d9efc223 | 940 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
941 | |
942 | /* This can happen on COOKIE-ECHO resend. Only | |
943 | * one chunk can get bundled with a COOKIE-ECHO. | |
944 | */ | |
945 | if (packet->has_cookie_echo) | |
946 | goto sctp_flush_out; | |
947 | ||
948 | /* Don't send new data if there is still data | |
949 | * waiting to retransmit. | |
950 | */ | |
951 | if (!list_empty(&q->retransmit)) | |
952 | goto sctp_flush_out; | |
953 | } | |
954 | ||
46d5a808 VY |
955 | /* Apply Max.Burst limitation to the current transport in |
956 | * case it will be used for new data. We are going to | |
957 | * rest it before we return, but we want to apply the limit | |
958 | * to the currently queued data. | |
959 | */ | |
960 | if (transport) | |
961 | sctp_transport_burst_limited(transport); | |
962 | ||
1da177e4 | 963 | /* Finally, transmit new packets. */ |
1da177e4 LT |
964 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
965 | /* RFC 2960 6.5 Every DATA chunk MUST carry a valid | |
966 | * stream identifier. | |
967 | */ | |
968 | if (chunk->sinfo.sinfo_stream >= | |
969 | asoc->c.sinit_num_ostreams) { | |
970 | ||
971 | /* Mark as failed send. */ | |
972 | sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); | |
973 | sctp_chunk_free(chunk); | |
974 | continue; | |
975 | } | |
976 | ||
977 | /* Has this chunk expired? */ | |
978 | if (sctp_chunk_abandoned(chunk)) { | |
979 | sctp_chunk_fail(chunk, 0); | |
980 | sctp_chunk_free(chunk); | |
981 | continue; | |
982 | } | |
983 | ||
984 | /* If there is a specified transport, use it. | |
985 | * Otherwise, we want to use the active path. | |
986 | */ | |
987 | new_transport = chunk->transport; | |
3f7a87d2 | 988 | if (!new_transport || |
ad8fec17 SS |
989 | ((new_transport->state == SCTP_INACTIVE) || |
990 | (new_transport->state == SCTP_UNCONFIRMED))) | |
1da177e4 | 991 | new_transport = asoc->peer.active_path; |
f207c050 MH |
992 | if (new_transport->state == SCTP_UNCONFIRMED) |
993 | continue; | |
1da177e4 LT |
994 | |
995 | /* Change packets if necessary. */ | |
996 | if (new_transport != transport) { | |
997 | transport = new_transport; | |
998 | ||
999 | /* Schedule to have this transport's | |
1000 | * packet flushed. | |
1001 | */ | |
1002 | if (list_empty(&transport->send_ready)) { | |
1003 | list_add_tail(&transport->send_ready, | |
1004 | &transport_list); | |
1005 | } | |
1006 | ||
1007 | packet = &transport->packet; | |
1008 | sctp_packet_config(packet, vtag, | |
1009 | asoc->peer.ecn_capable); | |
46d5a808 VY |
1010 | /* We've switched transports, so apply the |
1011 | * Burst limit to the new transport. | |
1012 | */ | |
1013 | sctp_transport_burst_limited(transport); | |
1da177e4 LT |
1014 | } |
1015 | ||
1016 | SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ", | |
1017 | q, chunk, | |
1018 | chunk && chunk->chunk_hdr ? | |
1019 | sctp_cname(SCTP_ST_CHUNK( | |
1020 | chunk->chunk_hdr->type)) | |
1021 | : "Illegal Chunk"); | |
1022 | ||
1023 | SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head " | |
1024 | "%p skb->users %d.\n", | |
1025 | ntohl(chunk->subh.data_hdr->tsn), | |
1026 | chunk->skb ?chunk->skb->head : NULL, | |
1027 | chunk->skb ? | |
1028 | atomic_read(&chunk->skb->users) : -1); | |
1029 | ||
1030 | /* Add the chunk to the packet. */ | |
2e3216cd | 1031 | status = sctp_packet_transmit_chunk(packet, chunk, 0); |
1da177e4 LT |
1032 | |
1033 | switch (status) { | |
1034 | case SCTP_XMIT_PMTU_FULL: | |
1035 | case SCTP_XMIT_RWND_FULL: | |
1036 | case SCTP_XMIT_NAGLE_DELAY: | |
1037 | /* We could not append this chunk, so put | |
1038 | * the chunk back on the output queue. | |
1039 | */ | |
1040 | SCTP_DEBUG_PRINTK("sctp_outq_flush: could " | |
1041 | "not transmit TSN: 0x%x, status: %d\n", | |
1042 | ntohl(chunk->subh.data_hdr->tsn), | |
1043 | status); | |
1044 | sctp_outq_head_data(q, chunk); | |
1045 | goto sctp_flush_out; | |
1046 | break; | |
1047 | ||
1048 | case SCTP_XMIT_OK: | |
b93d6471 WY |
1049 | /* The sender is in the SHUTDOWN-PENDING state, |
1050 | * The sender MAY set the I-bit in the DATA | |
1051 | * chunk header. | |
1052 | */ | |
1053 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) | |
1054 | chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; | |
1055 | ||
1da177e4 LT |
1056 | break; |
1057 | ||
1058 | default: | |
1059 | BUG(); | |
1060 | } | |
1061 | ||
d808ad9a | 1062 | /* BUG: We assume that the sctp_packet_transmit() |
1da177e4 LT |
1063 | * call below will succeed all the time and add the |
1064 | * chunk to the transmitted list and restart the | |
1065 | * timers. | |
1066 | * It is possible that the call can fail under OOM | |
1067 | * conditions. | |
1068 | * | |
1069 | * Is this really a problem? Won't this behave | |
1070 | * like a lost TSN? | |
1071 | */ | |
1072 | list_add_tail(&chunk->transmitted_list, | |
1073 | &transport->transmitted); | |
1074 | ||
d9efc223 | 1075 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
1076 | |
1077 | q->empty = 0; | |
1078 | ||
1079 | /* Only let one DATA chunk get bundled with a | |
1080 | * COOKIE-ECHO chunk. | |
1081 | */ | |
1082 | if (packet->has_cookie_echo) | |
1083 | goto sctp_flush_out; | |
1084 | } | |
1085 | break; | |
1086 | ||
1087 | default: | |
1088 | /* Do nothing. */ | |
1089 | break; | |
1090 | } | |
1091 | ||
1092 | sctp_flush_out: | |
1093 | ||
1094 | /* Before returning, examine all the transports touched in | |
1095 | * this call. Right now, we bluntly force clear all the | |
1096 | * transports. Things might change after we implement Nagle. | |
1097 | * But such an examination is still required. | |
1098 | * | |
1099 | * --xguo | |
1100 | */ | |
1101 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) { | |
1102 | struct sctp_transport *t = list_entry(ltransport, | |
1103 | struct sctp_transport, | |
1104 | send_ready); | |
1105 | packet = &t->packet; | |
1106 | if (!sctp_packet_empty(packet)) | |
1107 | error = sctp_packet_transmit(packet); | |
46d5a808 VY |
1108 | |
1109 | /* Clear the burst limited state, if any */ | |
1110 | sctp_transport_burst_reset(t); | |
1da177e4 LT |
1111 | } |
1112 | ||
1113 | return error; | |
1114 | } | |
1115 | ||
1116 | /* Update unack_data based on the incoming SACK chunk */ | |
1117 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
1118 | struct sctp_sackhdr *sack) | |
1119 | { | |
1120 | sctp_sack_variable_t *frags; | |
1121 | __u16 unack_data; | |
1122 | int i; | |
1123 | ||
1124 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
1125 | ||
1126 | frags = sack->variable; | |
1127 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
1128 | unack_data -= ((ntohs(frags[i].gab.end) - | |
1129 | ntohs(frags[i].gab.start) + 1)); | |
1130 | } | |
1131 | ||
1132 | assoc->unack_data = unack_data; | |
1133 | } | |
1134 | ||
1da177e4 LT |
1135 | /* This is where we REALLY process a SACK. |
1136 | * | |
1137 | * Process the SACK against the outqueue. Mostly, this just frees | |
1138 | * things off the transmitted queue. | |
1139 | */ | |
1140 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) | |
1141 | { | |
1142 | struct sctp_association *asoc = q->asoc; | |
1143 | struct sctp_transport *transport; | |
1144 | struct sctp_chunk *tchunk = NULL; | |
9dbc15f0 | 1145 | struct list_head *lchunk, *transport_list, *temp; |
1da177e4 LT |
1146 | sctp_sack_variable_t *frags = sack->variable; |
1147 | __u32 sack_ctsn, ctsn, tsn; | |
1148 | __u32 highest_tsn, highest_new_tsn; | |
1149 | __u32 sack_a_rwnd; | |
95c96174 | 1150 | unsigned int outstanding; |
1da177e4 LT |
1151 | struct sctp_transport *primary = asoc->peer.primary_path; |
1152 | int count_of_newacks = 0; | |
2cd9b822 | 1153 | int gap_ack_blocks; |
ea862c8d | 1154 | u8 accum_moved = 0; |
1da177e4 LT |
1155 | |
1156 | /* Grab the association's destination address list. */ | |
1157 | transport_list = &asoc->peer.transport_addr_list; | |
1158 | ||
1159 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
2cd9b822 | 1160 | gap_ack_blocks = ntohs(sack->num_gap_ack_blocks); |
1da177e4 LT |
1161 | /* |
1162 | * SFR-CACC algorithm: | |
1163 | * On receipt of a SACK the sender SHOULD execute the | |
1164 | * following statements. | |
1165 | * | |
1166 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1167 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1168 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1169 | * all destinations. | |
1da177e4 LT |
1170 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
1171 | * is set the receiver of the SACK MUST take the following actions: | |
1172 | * | |
1173 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1174 | * addresses. | |
ab5216a5 VY |
1175 | * |
1176 | * Only bother if changeover_active is set. Otherwise, this is | |
1177 | * totally suboptimal to do on every SACK. | |
1da177e4 | 1178 | */ |
ab5216a5 VY |
1179 | if (primary->cacc.changeover_active) { |
1180 | u8 clear_cycling = 0; | |
1181 | ||
1182 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1183 | primary->cacc.changeover_active = 0; | |
1184 | clear_cycling = 1; | |
1185 | } | |
1186 | ||
1187 | if (clear_cycling || gap_ack_blocks) { | |
1188 | list_for_each_entry(transport, transport_list, | |
1189 | transports) { | |
1190 | if (clear_cycling) | |
1191 | transport->cacc.cycling_changeover = 0; | |
1192 | if (gap_ack_blocks) | |
1193 | transport->cacc.cacc_saw_newack = 0; | |
1194 | } | |
1da177e4 LT |
1195 | } |
1196 | } | |
1197 | ||
1198 | /* Get the highest TSN in the sack. */ | |
1199 | highest_tsn = sack_ctsn; | |
2cd9b822 VY |
1200 | if (gap_ack_blocks) |
1201 | highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); | |
1da177e4 | 1202 | |
bfa0d984 | 1203 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) |
1da177e4 | 1204 | asoc->highest_sacked = highest_tsn; |
1da177e4 | 1205 | |
bfa0d984 | 1206 | highest_new_tsn = sack_ctsn; |
2cd9b822 | 1207 | |
1da177e4 LT |
1208 | /* Run through the retransmit queue. Credit bytes received |
1209 | * and free those chunks that we can. | |
1210 | */ | |
bfa0d984 | 1211 | sctp_check_transmitted(q, &q->retransmit, NULL, sack, &highest_new_tsn); |
1da177e4 LT |
1212 | |
1213 | /* Run through the transmitted queue. | |
1214 | * Credit bytes received and free those chunks which we can. | |
1215 | * | |
1216 | * This is a MASSIVE candidate for optimization. | |
1217 | */ | |
9dbc15f0 | 1218 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 | 1219 | sctp_check_transmitted(q, &transport->transmitted, |
bfa0d984 | 1220 | transport, sack, &highest_new_tsn); |
1da177e4 LT |
1221 | /* |
1222 | * SFR-CACC algorithm: | |
1223 | * C) Let count_of_newacks be the number of | |
1224 | * destinations for which cacc_saw_newack is set. | |
1225 | */ | |
1226 | if (transport->cacc.cacc_saw_newack) | |
1227 | count_of_newacks ++; | |
1228 | } | |
1229 | ||
ea862c8d VY |
1230 | /* Move the Cumulative TSN Ack Point if appropriate. */ |
1231 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) { | |
1232 | asoc->ctsn_ack_point = sack_ctsn; | |
1233 | accum_moved = 1; | |
1234 | } | |
1235 | ||
2cd9b822 | 1236 | if (gap_ack_blocks) { |
ea862c8d VY |
1237 | |
1238 | if (asoc->fast_recovery && accum_moved) | |
1239 | highest_new_tsn = highest_tsn; | |
1240 | ||
2cd9b822 VY |
1241 | list_for_each_entry(transport, transport_list, transports) |
1242 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1243 | highest_new_tsn, count_of_newacks); | |
1da177e4 LT |
1244 | } |
1245 | ||
1da177e4 LT |
1246 | /* Update unack_data field in the assoc. */ |
1247 | sctp_sack_update_unack_data(asoc, sack); | |
1248 | ||
1249 | ctsn = asoc->ctsn_ack_point; | |
1250 | ||
1251 | /* Throw away stuff rotting on the sack queue. */ | |
1252 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1253 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1254 | transmitted_list); | |
1255 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
5f9646c3 VY |
1256 | if (TSN_lte(tsn, ctsn)) { |
1257 | list_del_init(&tchunk->transmitted_list); | |
1da177e4 | 1258 | sctp_chunk_free(tchunk); |
5f9646c3 | 1259 | } |
1da177e4 LT |
1260 | } |
1261 | ||
1262 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1263 | * number of bytes still outstanding after processing the | |
1264 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1265 | */ | |
1266 | ||
1267 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
1268 | outstanding = q->outstanding_bytes; | |
1269 | ||
1270 | if (outstanding < sack_a_rwnd) | |
1271 | sack_a_rwnd -= outstanding; | |
1272 | else | |
1273 | sack_a_rwnd = 0; | |
1274 | ||
1275 | asoc->peer.rwnd = sack_a_rwnd; | |
1276 | ||
1277 | sctp_generate_fwdtsn(q, sack_ctsn); | |
1278 | ||
1279 | SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n", | |
0dc47877 | 1280 | __func__, sack_ctsn); |
1da177e4 LT |
1281 | SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, " |
1282 | "%p is 0x%x. Adv peer ack point: 0x%x\n", | |
0dc47877 | 1283 | __func__, asoc, ctsn, asoc->adv_peer_ack_point); |
1da177e4 LT |
1284 | |
1285 | /* See if all chunks are acked. | |
1286 | * Make sure the empty queue handler will get run later. | |
1287 | */ | |
79af02c2 | 1288 | q->empty = (list_empty(&q->out_chunk_list) && |
79af02c2 | 1289 | list_empty(&q->retransmit)); |
1da177e4 LT |
1290 | if (!q->empty) |
1291 | goto finish; | |
1292 | ||
9dbc15f0 | 1293 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 LT |
1294 | q->empty = q->empty && list_empty(&transport->transmitted); |
1295 | if (!q->empty) | |
1296 | goto finish; | |
1297 | } | |
1298 | ||
1299 | SCTP_DEBUG_PRINTK("sack queue is empty.\n"); | |
1300 | finish: | |
1301 | return q->empty; | |
1302 | } | |
1303 | ||
1304 | /* Is the outqueue empty? */ | |
1305 | int sctp_outq_is_empty(const struct sctp_outq *q) | |
1306 | { | |
1307 | return q->empty; | |
1308 | } | |
1309 | ||
1310 | /******************************************************************** | |
1311 | * 2nd Level Abstractions | |
1312 | ********************************************************************/ | |
1313 | ||
1314 | /* Go through a transport's transmitted list or the association's retransmit | |
1315 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1316 | * The retransmit list will not have an associated transport. | |
1317 | * | |
1318 | * I added coherent debug information output. --xguo | |
1319 | * | |
1320 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1321 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1322 | * KEPT TSN6-TSN7, etc. | |
1323 | */ | |
1324 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1325 | struct list_head *transmitted_queue, | |
1326 | struct sctp_transport *transport, | |
1327 | struct sctp_sackhdr *sack, | |
bfa0d984 | 1328 | __u32 *highest_new_tsn_in_sack) |
1da177e4 LT |
1329 | { |
1330 | struct list_head *lchunk; | |
1331 | struct sctp_chunk *tchunk; | |
1332 | struct list_head tlist; | |
1333 | __u32 tsn; | |
1334 | __u32 sack_ctsn; | |
1335 | __u32 rtt; | |
1336 | __u8 restart_timer = 0; | |
1337 | int bytes_acked = 0; | |
31b02e15 | 1338 | int migrate_bytes = 0; |
1da177e4 LT |
1339 | |
1340 | /* These state variables are for coherent debug output. --xguo */ | |
1341 | ||
1342 | #if SCTP_DEBUG | |
1343 | __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */ | |
1344 | __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */ | |
1345 | __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */ | |
1346 | __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */ | |
1347 | ||
1348 | /* 0 : The last TSN was ACKed. | |
1349 | * 1 : The last TSN was NOT ACKed (i.e. KEPT). | |
1350 | * -1: We need to initialize. | |
1351 | */ | |
1352 | int dbg_prt_state = -1; | |
1353 | #endif /* SCTP_DEBUG */ | |
1354 | ||
1355 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
1356 | ||
1357 | INIT_LIST_HEAD(&tlist); | |
1358 | ||
1359 | /* The while loop will skip empty transmitted queues. */ | |
1360 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1361 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1362 | transmitted_list); | |
1363 | ||
1364 | if (sctp_chunk_abandoned(tchunk)) { | |
1365 | /* Move the chunk to abandoned list. */ | |
1366 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
1367 | |
1368 | /* If this chunk has not been acked, stop | |
1369 | * considering it as 'outstanding'. | |
1370 | */ | |
1371 | if (!tchunk->tsn_gap_acked) { | |
31b02e15 VY |
1372 | if (tchunk->transport) |
1373 | tchunk->transport->flight_size -= | |
1374 | sctp_data_size(tchunk); | |
8c4a2d41 VY |
1375 | q->outstanding_bytes -= sctp_data_size(tchunk); |
1376 | } | |
1da177e4 LT |
1377 | continue; |
1378 | } | |
1379 | ||
1380 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1381 | if (sctp_acked(sack, tsn)) { | |
1382 | /* If this queue is the retransmit queue, the | |
1383 | * retransmit timer has already reclaimed | |
1384 | * the outstanding bytes for this chunk, so only | |
1385 | * count bytes associated with a transport. | |
1386 | */ | |
1387 | if (transport) { | |
1388 | /* If this chunk is being used for RTT | |
1389 | * measurement, calculate the RTT and update | |
1390 | * the RTO using this value. | |
1391 | * | |
1392 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1393 | * MUST NOT be made using packets that were | |
1394 | * retransmitted (and thus for which it is | |
1395 | * ambiguous whether the reply was for the | |
1396 | * first instance of the packet or a later | |
1397 | * instance). | |
1398 | */ | |
d808ad9a | 1399 | if (!tchunk->tsn_gap_acked && |
1da177e4 | 1400 | tchunk->rtt_in_progress) { |
4c9f5d53 | 1401 | tchunk->rtt_in_progress = 0; |
1da177e4 LT |
1402 | rtt = jiffies - tchunk->sent_at; |
1403 | sctp_transport_update_rto(transport, | |
1404 | rtt); | |
1405 | } | |
1406 | } | |
31b02e15 VY |
1407 | |
1408 | /* If the chunk hasn't been marked as ACKED, | |
1409 | * mark it and account bytes_acked if the | |
1410 | * chunk had a valid transport (it will not | |
1411 | * have a transport if ASCONF had deleted it | |
1412 | * while DATA was outstanding). | |
1413 | */ | |
1414 | if (!tchunk->tsn_gap_acked) { | |
1415 | tchunk->tsn_gap_acked = 1; | |
bfa0d984 | 1416 | *highest_new_tsn_in_sack = tsn; |
31b02e15 VY |
1417 | bytes_acked += sctp_data_size(tchunk); |
1418 | if (!tchunk->transport) | |
1419 | migrate_bytes += sctp_data_size(tchunk); | |
1420 | } | |
1421 | ||
d808ad9a | 1422 | if (TSN_lte(tsn, sack_ctsn)) { |
1da177e4 LT |
1423 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
1424 | * | |
1425 | * R3) Whenever a SACK is received | |
1426 | * that acknowledges the DATA chunk | |
1427 | * with the earliest outstanding TSN | |
1428 | * for that address, restart T3-rtx | |
1429 | * timer for that address with its | |
1430 | * current RTO. | |
1431 | */ | |
1432 | restart_timer = 1; | |
1433 | ||
1434 | if (!tchunk->tsn_gap_acked) { | |
1da177e4 LT |
1435 | /* |
1436 | * SFR-CACC algorithm: | |
1437 | * 2) If the SACK contains gap acks | |
1438 | * and the flag CHANGEOVER_ACTIVE is | |
1439 | * set the receiver of the SACK MUST | |
1440 | * take the following action: | |
1441 | * | |
1442 | * B) For each TSN t being acked that | |
1443 | * has not been acked in any SACK so | |
1444 | * far, set cacc_saw_newack to 1 for | |
1445 | * the destination that the TSN was | |
1446 | * sent to. | |
1447 | */ | |
1448 | if (transport && | |
1449 | sack->num_gap_ack_blocks && | |
1450 | q->asoc->peer.primary_path->cacc. | |
1451 | changeover_active) | |
1452 | transport->cacc.cacc_saw_newack | |
1453 | = 1; | |
1454 | } | |
1455 | ||
1456 | list_add_tail(&tchunk->transmitted_list, | |
1457 | &q->sacked); | |
1458 | } else { | |
1459 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1460 | * M2) Each time a SACK arrives reporting | |
1461 | * 'Stray DATA chunk(s)' record the highest TSN | |
1462 | * reported as newly acknowledged, call this | |
1463 | * value 'HighestTSNinSack'. A newly | |
1464 | * acknowledged DATA chunk is one not | |
1465 | * previously acknowledged in a SACK. | |
1466 | * | |
1467 | * When the SCTP sender of data receives a SACK | |
1468 | * chunk that acknowledges, for the first time, | |
1469 | * the receipt of a DATA chunk, all the still | |
1470 | * unacknowledged DATA chunks whose TSN is | |
1471 | * older than that newly acknowledged DATA | |
1472 | * chunk, are qualified as 'Stray DATA chunks'. | |
1473 | */ | |
1da177e4 LT |
1474 | list_add_tail(lchunk, &tlist); |
1475 | } | |
1476 | ||
1477 | #if SCTP_DEBUG | |
1478 | switch (dbg_prt_state) { | |
1479 | case 0: /* last TSN was ACKed */ | |
1480 | if (dbg_last_ack_tsn + 1 == tsn) { | |
1481 | /* This TSN belongs to the | |
1482 | * current ACK range. | |
1483 | */ | |
1484 | break; | |
1485 | } | |
1486 | ||
1487 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
1488 | /* Display the end of the | |
1489 | * current range. | |
1490 | */ | |
145ce502 JP |
1491 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1492 | dbg_last_ack_tsn); | |
1da177e4 LT |
1493 | } |
1494 | ||
1495 | /* Start a new range. */ | |
145ce502 | 1496 | SCTP_DEBUG_PRINTK_CONT(",%08x", tsn); |
1da177e4 LT |
1497 | dbg_ack_tsn = tsn; |
1498 | break; | |
1499 | ||
1500 | case 1: /* The last TSN was NOT ACKed. */ | |
1501 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
1502 | /* Display the end of current range. */ | |
145ce502 JP |
1503 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1504 | dbg_last_kept_tsn); | |
1da177e4 LT |
1505 | } |
1506 | ||
145ce502 | 1507 | SCTP_DEBUG_PRINTK_CONT("\n"); |
1da177e4 LT |
1508 | |
1509 | /* FALL THROUGH... */ | |
1510 | default: | |
1511 | /* This is the first-ever TSN we examined. */ | |
1512 | /* Start a new range of ACK-ed TSNs. */ | |
1513 | SCTP_DEBUG_PRINTK("ACKed: %08x", tsn); | |
1514 | dbg_prt_state = 0; | |
1515 | dbg_ack_tsn = tsn; | |
3ff50b79 | 1516 | } |
1da177e4 LT |
1517 | |
1518 | dbg_last_ack_tsn = tsn; | |
1519 | #endif /* SCTP_DEBUG */ | |
1520 | ||
1521 | } else { | |
1522 | if (tchunk->tsn_gap_acked) { | |
1523 | SCTP_DEBUG_PRINTK("%s: Receiver reneged on " | |
1524 | "data TSN: 0x%x\n", | |
0dc47877 | 1525 | __func__, |
1da177e4 LT |
1526 | tsn); |
1527 | tchunk->tsn_gap_acked = 0; | |
1528 | ||
31b02e15 VY |
1529 | if (tchunk->transport) |
1530 | bytes_acked -= sctp_data_size(tchunk); | |
1da177e4 LT |
1531 | |
1532 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1533 | * | |
1534 | * R4) Whenever a SACK is received missing a | |
1535 | * TSN that was previously acknowledged via a | |
1536 | * Gap Ack Block, start T3-rtx for the | |
1537 | * destination address to which the DATA | |
1538 | * chunk was originally | |
1539 | * transmitted if it is not already running. | |
1540 | */ | |
1541 | restart_timer = 1; | |
1542 | } | |
1543 | ||
1544 | list_add_tail(lchunk, &tlist); | |
1545 | ||
1546 | #if SCTP_DEBUG | |
1547 | /* See the above comments on ACK-ed TSNs. */ | |
1548 | switch (dbg_prt_state) { | |
1549 | case 1: | |
1550 | if (dbg_last_kept_tsn + 1 == tsn) | |
1551 | break; | |
1552 | ||
1553 | if (dbg_last_kept_tsn != dbg_kept_tsn) | |
145ce502 JP |
1554 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1555 | dbg_last_kept_tsn); | |
1da177e4 | 1556 | |
145ce502 | 1557 | SCTP_DEBUG_PRINTK_CONT(",%08x", tsn); |
1da177e4 LT |
1558 | dbg_kept_tsn = tsn; |
1559 | break; | |
1560 | ||
1561 | case 0: | |
1562 | if (dbg_last_ack_tsn != dbg_ack_tsn) | |
145ce502 JP |
1563 | SCTP_DEBUG_PRINTK_CONT("-%08x", |
1564 | dbg_last_ack_tsn); | |
1565 | SCTP_DEBUG_PRINTK_CONT("\n"); | |
1da177e4 LT |
1566 | |
1567 | /* FALL THROUGH... */ | |
1568 | default: | |
1569 | SCTP_DEBUG_PRINTK("KEPT: %08x",tsn); | |
1570 | dbg_prt_state = 1; | |
1571 | dbg_kept_tsn = tsn; | |
3ff50b79 | 1572 | } |
1da177e4 LT |
1573 | |
1574 | dbg_last_kept_tsn = tsn; | |
1575 | #endif /* SCTP_DEBUG */ | |
1576 | } | |
1577 | } | |
1578 | ||
1579 | #if SCTP_DEBUG | |
1580 | /* Finish off the last range, displaying its ending TSN. */ | |
1581 | switch (dbg_prt_state) { | |
1582 | case 0: | |
1583 | if (dbg_last_ack_tsn != dbg_ack_tsn) { | |
145ce502 | 1584 | SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_ack_tsn); |
1da177e4 | 1585 | } else { |
145ce502 | 1586 | SCTP_DEBUG_PRINTK_CONT("\n"); |
1da177e4 LT |
1587 | } |
1588 | break; | |
1589 | ||
1590 | case 1: | |
1591 | if (dbg_last_kept_tsn != dbg_kept_tsn) { | |
145ce502 | 1592 | SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_kept_tsn); |
1da177e4 | 1593 | } else { |
145ce502 | 1594 | SCTP_DEBUG_PRINTK_CONT("\n"); |
1da177e4 | 1595 | } |
3ff50b79 | 1596 | } |
1da177e4 LT |
1597 | #endif /* SCTP_DEBUG */ |
1598 | if (transport) { | |
1599 | if (bytes_acked) { | |
f8d96052 TG |
1600 | struct sctp_association *asoc = transport->asoc; |
1601 | ||
31b02e15 VY |
1602 | /* We may have counted DATA that was migrated |
1603 | * to this transport due to DEL-IP operation. | |
1604 | * Subtract those bytes, since the were never | |
1605 | * send on this transport and shouldn't be | |
1606 | * credited to this transport. | |
1607 | */ | |
1608 | bytes_acked -= migrate_bytes; | |
1609 | ||
1da177e4 LT |
1610 | /* 8.2. When an outstanding TSN is acknowledged, |
1611 | * the endpoint shall clear the error counter of | |
1612 | * the destination transport address to which the | |
1613 | * DATA chunk was last sent. | |
1614 | * The association's overall error counter is | |
1615 | * also cleared. | |
1616 | */ | |
1617 | transport->error_count = 0; | |
1618 | transport->asoc->overall_error_count = 0; | |
1619 | ||
f8d96052 TG |
1620 | /* |
1621 | * While in SHUTDOWN PENDING, we may have started | |
1622 | * the T5 shutdown guard timer after reaching the | |
1623 | * retransmission limit. Stop that timer as soon | |
1624 | * as the receiver acknowledged any data. | |
1625 | */ | |
1626 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING && | |
1627 | del_timer(&asoc->timers | |
1628 | [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD])) | |
1629 | sctp_association_put(asoc); | |
1630 | ||
1da177e4 LT |
1631 | /* Mark the destination transport address as |
1632 | * active if it is not so marked. | |
1633 | */ | |
ad8fec17 SS |
1634 | if ((transport->state == SCTP_INACTIVE) || |
1635 | (transport->state == SCTP_UNCONFIRMED)) { | |
1da177e4 LT |
1636 | sctp_assoc_control_transport( |
1637 | transport->asoc, | |
1638 | transport, | |
1639 | SCTP_TRANSPORT_UP, | |
1640 | SCTP_RECEIVED_SACK); | |
1641 | } | |
1642 | ||
1643 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1644 | bytes_acked); | |
1645 | ||
1646 | transport->flight_size -= bytes_acked; | |
8b73a07c GJ |
1647 | if (transport->flight_size == 0) |
1648 | transport->partial_bytes_acked = 0; | |
31b02e15 | 1649 | q->outstanding_bytes -= bytes_acked + migrate_bytes; |
1da177e4 LT |
1650 | } else { |
1651 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1652 | * When a sender is doing zero window probing, it | |
1653 | * should not timeout the association if it continues | |
1654 | * to receive new packets from the receiver. The | |
1655 | * reason is that the receiver MAY keep its window | |
1656 | * closed for an indefinite time. | |
1657 | * A sender is doing zero window probing when the | |
1658 | * receiver's advertised window is zero, and there is | |
1659 | * only one data chunk in flight to the receiver. | |
f8d96052 TG |
1660 | * |
1661 | * Allow the association to timeout while in SHUTDOWN | |
1662 | * PENDING or SHUTDOWN RECEIVED in case the receiver | |
1663 | * stays in zero window mode forever. | |
1da177e4 LT |
1664 | */ |
1665 | if (!q->asoc->peer.rwnd && | |
1666 | !list_empty(&tlist) && | |
f8d96052 TG |
1667 | (sack_ctsn+2 == q->asoc->next_tsn) && |
1668 | q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) { | |
1da177e4 LT |
1669 | SCTP_DEBUG_PRINTK("%s: SACK received for zero " |
1670 | "window probe: %u\n", | |
0dc47877 | 1671 | __func__, sack_ctsn); |
1da177e4 LT |
1672 | q->asoc->overall_error_count = 0; |
1673 | transport->error_count = 0; | |
1674 | } | |
1675 | } | |
1676 | ||
1677 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1678 | * | |
1679 | * R2) Whenever all outstanding data sent to an address have | |
1680 | * been acknowledged, turn off the T3-rtx timer of that | |
1681 | * address. | |
1682 | */ | |
1683 | if (!transport->flight_size) { | |
1684 | if (timer_pending(&transport->T3_rtx_timer) && | |
1685 | del_timer(&transport->T3_rtx_timer)) { | |
1686 | sctp_transport_put(transport); | |
1687 | } | |
1688 | } else if (restart_timer) { | |
1689 | if (!mod_timer(&transport->T3_rtx_timer, | |
1690 | jiffies + transport->rto)) | |
1691 | sctp_transport_hold(transport); | |
1692 | } | |
1693 | } | |
1694 | ||
1695 | list_splice(&tlist, transmitted_queue); | |
1696 | } | |
1697 | ||
1698 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1699 | static void sctp_mark_missing(struct sctp_outq *q, | |
1700 | struct list_head *transmitted_queue, | |
1701 | struct sctp_transport *transport, | |
1702 | __u32 highest_new_tsn_in_sack, | |
1703 | int count_of_newacks) | |
1704 | { | |
1705 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1706 | __u32 tsn; |
1707 | char do_fast_retransmit = 0; | |
ea862c8d VY |
1708 | struct sctp_association *asoc = q->asoc; |
1709 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1da177e4 | 1710 | |
9dbc15f0 | 1711 | list_for_each_entry(chunk, transmitted_queue, transmitted_list) { |
1da177e4 | 1712 | |
1da177e4 LT |
1713 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1714 | ||
1715 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1716 | * 'Unacknowledged TSN's', if the TSN number of an | |
1717 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1718 | * value, increment the 'TSN.Missing.Report' count on that | |
1719 | * chunk if it has NOT been fast retransmitted or marked for | |
1720 | * fast retransmit already. | |
1721 | */ | |
c226ef9b | 1722 | if (chunk->fast_retransmit == SCTP_CAN_FRTX && |
1da177e4 LT |
1723 | !chunk->tsn_gap_acked && |
1724 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1725 | ||
1726 | /* SFR-CACC may require us to skip marking | |
1727 | * this chunk as missing. | |
1728 | */ | |
f246a7b7 VY |
1729 | if (!transport || !sctp_cacc_skip(primary, |
1730 | chunk->transport, | |
1731 | count_of_newacks, tsn)) { | |
1da177e4 LT |
1732 | chunk->tsn_missing_report++; |
1733 | ||
1734 | SCTP_DEBUG_PRINTK( | |
1735 | "%s: TSN 0x%x missing counter: %d\n", | |
0dc47877 | 1736 | __func__, tsn, |
1da177e4 LT |
1737 | chunk->tsn_missing_report); |
1738 | } | |
1739 | } | |
1740 | /* | |
1741 | * M4) If any DATA chunk is found to have a | |
1742 | * 'TSN.Missing.Report' | |
27852c26 | 1743 | * value larger than or equal to 3, mark that chunk for |
1da177e4 LT |
1744 | * retransmission and start the fast retransmit procedure. |
1745 | */ | |
1746 | ||
27852c26 | 1747 | if (chunk->tsn_missing_report >= 3) { |
c226ef9b | 1748 | chunk->fast_retransmit = SCTP_NEED_FRTX; |
1da177e4 LT |
1749 | do_fast_retransmit = 1; |
1750 | } | |
1751 | } | |
1752 | ||
1753 | if (transport) { | |
1754 | if (do_fast_retransmit) | |
1755 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1756 | ||
1757 | SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, " | |
1758 | "ssthresh: %d, flight_size: %d, pba: %d\n", | |
0dc47877 | 1759 | __func__, transport, transport->cwnd, |
d808ad9a | 1760 | transport->ssthresh, transport->flight_size, |
1da177e4 LT |
1761 | transport->partial_bytes_acked); |
1762 | } | |
1763 | } | |
1764 | ||
1765 | /* Is the given TSN acked by this packet? */ | |
1766 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1767 | { | |
1768 | int i; | |
1769 | sctp_sack_variable_t *frags; | |
1770 | __u16 gap; | |
1771 | __u32 ctsn = ntohl(sack->cum_tsn_ack); | |
1772 | ||
d808ad9a | 1773 | if (TSN_lte(tsn, ctsn)) |
1da177e4 LT |
1774 | goto pass; |
1775 | ||
1776 | /* 3.3.4 Selective Acknowledgement (SACK) (3): | |
1777 | * | |
1778 | * Gap Ack Blocks: | |
1779 | * These fields contain the Gap Ack Blocks. They are repeated | |
1780 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1781 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1782 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1783 | * Ack + Gap Ack Block Start) and less than or equal to | |
1784 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1785 | * Block are assumed to have been received correctly. | |
1786 | */ | |
1787 | ||
1788 | frags = sack->variable; | |
1789 | gap = tsn - ctsn; | |
1790 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { | |
1791 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && | |
1792 | TSN_lte(gap, ntohs(frags[i].gab.end))) | |
1793 | goto pass; | |
1794 | } | |
1795 | ||
1796 | return 0; | |
1797 | pass: | |
1798 | return 1; | |
1799 | } | |
1800 | ||
1801 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
9f81bcd9 | 1802 | int nskips, __be16 stream) |
1da177e4 LT |
1803 | { |
1804 | int i; | |
1805 | ||
1806 | for (i = 0; i < nskips; i++) { | |
1807 | if (skiplist[i].stream == stream) | |
1808 | return i; | |
1809 | } | |
1810 | return i; | |
1811 | } | |
1812 | ||
1813 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
1814 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) | |
1815 | { | |
1816 | struct sctp_association *asoc = q->asoc; | |
1817 | struct sctp_chunk *ftsn_chunk = NULL; | |
1818 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1819 | int nskips = 0; | |
1820 | int skip_pos = 0; | |
1821 | __u32 tsn; | |
1822 | struct sctp_chunk *chunk; | |
1823 | struct list_head *lchunk, *temp; | |
1824 | ||
76595024 WY |
1825 | if (!asoc->peer.prsctp_capable) |
1826 | return; | |
1827 | ||
1da177e4 LT |
1828 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
1829 | * received SACK. | |
d808ad9a | 1830 | * |
1da177e4 LT |
1831 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
1832 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1833 | */ | |
1834 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1835 | asoc->adv_peer_ack_point = ctsn; | |
1836 | ||
1837 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1838 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1839 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1840 | * shown in the following example: | |
1841 | * | |
1842 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1843 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
d808ad9a | 1844 | * |
1da177e4 LT |
1845 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
1846 | * normal SACK processing local advancement | |
1847 | * ... ... | |
1848 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1849 | * 103 abandoned 103 abandoned | |
1850 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1851 | * 105 105 | |
1852 | * 106 acked 106 acked | |
1853 | * ... ... | |
1854 | * | |
1855 | * In this example, the data sender successfully advanced the | |
1856 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1857 | */ | |
1858 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1859 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1860 | transmitted_list); | |
1861 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1862 | ||
1863 | /* Remove any chunks in the abandoned queue that are acked by | |
1864 | * the ctsn. | |
d808ad9a | 1865 | */ |
1da177e4 LT |
1866 | if (TSN_lte(tsn, ctsn)) { |
1867 | list_del_init(lchunk); | |
1da177e4 LT |
1868 | sctp_chunk_free(chunk); |
1869 | } else { | |
1870 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1871 | asoc->adv_peer_ack_point = tsn; | |
1872 | if (chunk->chunk_hdr->flags & | |
1873 | SCTP_DATA_UNORDERED) | |
1874 | continue; | |
1875 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1876 | nskips, | |
1877 | chunk->subh.data_hdr->stream); | |
1878 | ftsn_skip_arr[skip_pos].stream = | |
1879 | chunk->subh.data_hdr->stream; | |
1880 | ftsn_skip_arr[skip_pos].ssn = | |
1881 | chunk->subh.data_hdr->ssn; | |
1882 | if (skip_pos == nskips) | |
1883 | nskips++; | |
1884 | if (nskips == 10) | |
1885 | break; | |
1886 | } else | |
1887 | break; | |
1888 | } | |
1889 | } | |
1890 | ||
1891 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1892 | * is greater than the Cumulative TSN ACK carried in the received | |
1893 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1894 | * chunk containing the latest value of the | |
1895 | * "Advanced.Peer.Ack.Point". | |
1896 | * | |
1897 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1898 | * list each stream and sequence number in the forwarded TSN. This | |
1899 | * information will enable the receiver to easily find any | |
1900 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1901 | * SHOULD only be reported once; this means that if multiple | |
1902 | * abandoned messages occur in the same stream then only the | |
1903 | * highest abandoned stream sequence number is reported. If the | |
1904 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1905 | * the sender of the FORWARD TSN SHOULD lower the | |
1906 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1907 | * single MTU. | |
1908 | */ | |
1909 | if (asoc->adv_peer_ack_point > ctsn) | |
1910 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
d808ad9a | 1911 | nskips, &ftsn_skip_arr[0]); |
1da177e4 LT |
1912 | |
1913 | if (ftsn_chunk) { | |
79af02c2 | 1914 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
1da177e4 LT |
1915 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
1916 | } | |
1917 | } |