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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, | |
edfee033 | 66 | union sctp_addr *saddr, |
1da177e4 | 67 | struct sctp_sackhdr *sack, |
bfa0d984 | 68 | __u32 *highest_new_tsn); |
1da177e4 LT |
69 | |
70 | static void sctp_mark_missing(struct sctp_outq *q, | |
71 | struct list_head *transmitted_queue, | |
72 | struct sctp_transport *transport, | |
73 | __u32 highest_new_tsn, | |
74 | int count_of_newacks); | |
75 | ||
76 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); | |
77 | ||
abd0b198 AB |
78 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout); |
79 | ||
1da177e4 LT |
80 | /* Add data to the front of the queue. */ |
81 | static inline void sctp_outq_head_data(struct sctp_outq *q, | |
82 | struct sctp_chunk *ch) | |
83 | { | |
79af02c2 | 84 | list_add(&ch->list, &q->out_chunk_list); |
1da177e4 | 85 | q->out_qlen += ch->skb->len; |
1da177e4 LT |
86 | } |
87 | ||
88 | /* Take data from the front of the queue. */ | |
89 | static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) | |
90 | { | |
79af02c2 DM |
91 | struct sctp_chunk *ch = NULL; |
92 | ||
93 | if (!list_empty(&q->out_chunk_list)) { | |
94 | struct list_head *entry = q->out_chunk_list.next; | |
95 | ||
96 | ch = list_entry(entry, struct sctp_chunk, list); | |
97 | list_del_init(entry); | |
1da177e4 | 98 | q->out_qlen -= ch->skb->len; |
79af02c2 | 99 | } |
1da177e4 LT |
100 | return ch; |
101 | } | |
102 | /* Add data chunk to the end of the queue. */ | |
103 | static inline void sctp_outq_tail_data(struct sctp_outq *q, | |
104 | struct sctp_chunk *ch) | |
105 | { | |
79af02c2 | 106 | list_add_tail(&ch->list, &q->out_chunk_list); |
1da177e4 | 107 | q->out_qlen += ch->skb->len; |
1da177e4 LT |
108 | } |
109 | ||
110 | /* | |
111 | * SFR-CACC algorithm: | |
112 | * D) If count_of_newacks is greater than or equal to 2 | |
113 | * and t was not sent to the current primary then the | |
114 | * sender MUST NOT increment missing report count for t. | |
115 | */ | |
116 | static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, | |
117 | struct sctp_transport *transport, | |
118 | int count_of_newacks) | |
119 | { | |
120 | if (count_of_newacks >=2 && transport != primary) | |
121 | return 1; | |
122 | return 0; | |
123 | } | |
124 | ||
125 | /* | |
126 | * SFR-CACC algorithm: | |
127 | * F) If count_of_newacks is less than 2, let d be the | |
128 | * destination to which t was sent. If cacc_saw_newack | |
129 | * is 0 for destination d, then the sender MUST NOT | |
130 | * increment missing report count for t. | |
131 | */ | |
132 | static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, | |
133 | int count_of_newacks) | |
134 | { | |
f246a7b7 VY |
135 | if (count_of_newacks < 2 && |
136 | (transport && !transport->cacc.cacc_saw_newack)) | |
1da177e4 LT |
137 | return 1; |
138 | return 0; | |
139 | } | |
140 | ||
141 | /* | |
142 | * SFR-CACC algorithm: | |
143 | * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD | |
144 | * execute steps C, D, F. | |
145 | * | |
146 | * C has been implemented in sctp_outq_sack | |
147 | */ | |
148 | static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, | |
149 | struct sctp_transport *transport, | |
150 | int count_of_newacks) | |
151 | { | |
152 | if (!primary->cacc.cycling_changeover) { | |
153 | if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks)) | |
154 | return 1; | |
155 | if (sctp_cacc_skip_3_1_f(transport, count_of_newacks)) | |
156 | return 1; | |
157 | return 0; | |
158 | } | |
159 | return 0; | |
160 | } | |
161 | ||
162 | /* | |
163 | * SFR-CACC algorithm: | |
164 | * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less | |
165 | * than next_tsn_at_change of the current primary, then | |
166 | * the sender MUST NOT increment missing report count | |
167 | * for t. | |
168 | */ | |
169 | static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) | |
170 | { | |
171 | if (primary->cacc.cycling_changeover && | |
172 | TSN_lt(tsn, primary->cacc.next_tsn_at_change)) | |
173 | return 1; | |
174 | return 0; | |
175 | } | |
176 | ||
177 | /* | |
178 | * SFR-CACC algorithm: | |
179 | * 3) If the missing report count for TSN t is to be | |
180 | * incremented according to [RFC2960] and | |
181 | * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, | |
25985edc | 182 | * then the sender MUST further execute steps 3.1 and |
1da177e4 LT |
183 | * 3.2 to determine if the missing report count for |
184 | * TSN t SHOULD NOT be incremented. | |
185 | * | |
186 | * 3.3) If 3.1 and 3.2 do not dictate that the missing | |
187 | * report count for t should not be incremented, then | |
25985edc | 188 | * the sender SHOULD increment missing report count for |
1da177e4 LT |
189 | * t (according to [RFC2960] and [SCTP_STEWART_2002]). |
190 | */ | |
191 | static inline int sctp_cacc_skip(struct sctp_transport *primary, | |
192 | struct sctp_transport *transport, | |
193 | int count_of_newacks, | |
194 | __u32 tsn) | |
195 | { | |
196 | if (primary->cacc.changeover_active && | |
f64f9e71 JP |
197 | (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) || |
198 | sctp_cacc_skip_3_2(primary, tsn))) | |
1da177e4 LT |
199 | return 1; |
200 | return 0; | |
201 | } | |
202 | ||
203 | /* Initialize an existing sctp_outq. This does the boring stuff. | |
204 | * You still need to define handlers if you really want to DO | |
205 | * something with this structure... | |
206 | */ | |
207 | void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) | |
208 | { | |
c5c7774d NH |
209 | memset(q, 0, sizeof(struct sctp_outq)); |
210 | ||
1da177e4 | 211 | q->asoc = asoc; |
79af02c2 DM |
212 | INIT_LIST_HEAD(&q->out_chunk_list); |
213 | INIT_LIST_HEAD(&q->control_chunk_list); | |
1da177e4 LT |
214 | INIT_LIST_HEAD(&q->retransmit); |
215 | INIT_LIST_HEAD(&q->sacked); | |
216 | INIT_LIST_HEAD(&q->abandoned); | |
217 | ||
1da177e4 | 218 | q->empty = 1; |
1da177e4 LT |
219 | } |
220 | ||
221 | /* Free the outqueue structure and any related pending chunks. | |
222 | */ | |
2f94aabd | 223 | static void __sctp_outq_teardown(struct sctp_outq *q) |
1da177e4 LT |
224 | { |
225 | struct sctp_transport *transport; | |
9dbc15f0 | 226 | struct list_head *lchunk, *temp; |
79af02c2 | 227 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
228 | |
229 | /* Throw away unacknowledged chunks. */ | |
9dbc15f0 RD |
230 | list_for_each_entry(transport, &q->asoc->peer.transport_addr_list, |
231 | transports) { | |
1da177e4 LT |
232 | while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) { |
233 | chunk = list_entry(lchunk, struct sctp_chunk, | |
234 | transmitted_list); | |
235 | /* Mark as part of a failed message. */ | |
236 | sctp_chunk_fail(chunk, q->error); | |
237 | sctp_chunk_free(chunk); | |
238 | } | |
239 | } | |
240 | ||
241 | /* Throw away chunks that have been gap ACKed. */ | |
242 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
243 | list_del_init(lchunk); | |
244 | chunk = list_entry(lchunk, struct sctp_chunk, | |
245 | transmitted_list); | |
246 | sctp_chunk_fail(chunk, q->error); | |
247 | sctp_chunk_free(chunk); | |
248 | } | |
249 | ||
250 | /* Throw away any chunks in the retransmit queue. */ | |
251 | list_for_each_safe(lchunk, temp, &q->retransmit) { | |
252 | list_del_init(lchunk); | |
253 | chunk = list_entry(lchunk, struct sctp_chunk, | |
254 | transmitted_list); | |
255 | sctp_chunk_fail(chunk, q->error); | |
256 | sctp_chunk_free(chunk); | |
257 | } | |
258 | ||
259 | /* Throw away any chunks that are in the abandoned queue. */ | |
260 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
261 | list_del_init(lchunk); | |
262 | chunk = list_entry(lchunk, struct sctp_chunk, | |
263 | transmitted_list); | |
264 | sctp_chunk_fail(chunk, q->error); | |
265 | sctp_chunk_free(chunk); | |
266 | } | |
267 | ||
268 | /* Throw away any leftover data chunks. */ | |
269 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { | |
270 | ||
271 | /* Mark as send failure. */ | |
272 | sctp_chunk_fail(chunk, q->error); | |
273 | sctp_chunk_free(chunk); | |
274 | } | |
275 | ||
1da177e4 | 276 | /* Throw away any leftover control chunks. */ |
79af02c2 DM |
277 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
278 | list_del_init(&chunk->list); | |
1da177e4 | 279 | sctp_chunk_free(chunk); |
79af02c2 | 280 | } |
1da177e4 LT |
281 | } |
282 | ||
2f94aabd NH |
283 | void sctp_outq_teardown(struct sctp_outq *q) |
284 | { | |
285 | __sctp_outq_teardown(q); | |
286 | sctp_outq_init(q->asoc, q); | |
287 | } | |
288 | ||
1da177e4 LT |
289 | /* Free the outqueue structure and any related pending chunks. */ |
290 | void sctp_outq_free(struct sctp_outq *q) | |
291 | { | |
292 | /* Throw away leftover chunks. */ | |
2f94aabd | 293 | __sctp_outq_teardown(q); |
1da177e4 LT |
294 | } |
295 | ||
296 | /* Put a new chunk in an sctp_outq. */ | |
297 | int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) | |
298 | { | |
b01a2407 | 299 | struct net *net = sock_net(q->asoc->base.sk); |
1da177e4 LT |
300 | int error = 0; |
301 | ||
bb33381d DB |
302 | pr_debug("%s: outq:%p, chunk:%p[%s]\n", __func__, q, chunk, |
303 | chunk && chunk->chunk_hdr ? | |
304 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
305 | "illegal chunk"); | |
1da177e4 LT |
306 | |
307 | /* If it is data, queue it up, otherwise, send it | |
308 | * immediately. | |
309 | */ | |
ec7b9519 | 310 | if (sctp_chunk_is_data(chunk)) { |
1da177e4 LT |
311 | /* Is it OK to queue data chunks? */ |
312 | /* From 9. Termination of Association | |
313 | * | |
314 | * When either endpoint performs a shutdown, the | |
315 | * association on each peer will stop accepting new | |
316 | * data from its user and only deliver data in queue | |
317 | * at the time of sending or receiving the SHUTDOWN | |
318 | * chunk. | |
319 | */ | |
320 | switch (q->asoc->state) { | |
1da177e4 LT |
321 | case SCTP_STATE_CLOSED: |
322 | case SCTP_STATE_SHUTDOWN_PENDING: | |
323 | case SCTP_STATE_SHUTDOWN_SENT: | |
324 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
325 | case SCTP_STATE_SHUTDOWN_ACK_SENT: | |
326 | /* Cannot send after transport endpoint shutdown */ | |
327 | error = -ESHUTDOWN; | |
328 | break; | |
329 | ||
330 | default: | |
bb33381d DB |
331 | pr_debug("%s: outqueueing: outq:%p, chunk:%p[%s])\n", |
332 | __func__, q, chunk, chunk && chunk->chunk_hdr ? | |
333 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
334 | "illegal chunk"); | |
1da177e4 LT |
335 | |
336 | sctp_outq_tail_data(q, chunk); | |
337 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
b01a2407 | 338 | SCTP_INC_STATS(net, SCTP_MIB_OUTUNORDERCHUNKS); |
1da177e4 | 339 | else |
b01a2407 | 340 | SCTP_INC_STATS(net, SCTP_MIB_OUTORDERCHUNKS); |
1da177e4 LT |
341 | q->empty = 0; |
342 | break; | |
3ff50b79 | 343 | } |
1da177e4 | 344 | } else { |
79af02c2 | 345 | list_add_tail(&chunk->list, &q->control_chunk_list); |
b01a2407 | 346 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
347 | } |
348 | ||
349 | if (error < 0) | |
350 | return error; | |
351 | ||
352 | if (!q->cork) | |
353 | error = sctp_outq_flush(q, 0); | |
354 | ||
355 | return error; | |
356 | } | |
357 | ||
358 | /* Insert a chunk into the sorted list based on the TSNs. The retransmit list | |
359 | * and the abandoned list are in ascending order. | |
360 | */ | |
361 | static void sctp_insert_list(struct list_head *head, struct list_head *new) | |
362 | { | |
363 | struct list_head *pos; | |
364 | struct sctp_chunk *nchunk, *lchunk; | |
365 | __u32 ntsn, ltsn; | |
366 | int done = 0; | |
367 | ||
368 | nchunk = list_entry(new, struct sctp_chunk, transmitted_list); | |
369 | ntsn = ntohl(nchunk->subh.data_hdr->tsn); | |
370 | ||
371 | list_for_each(pos, head) { | |
372 | lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); | |
373 | ltsn = ntohl(lchunk->subh.data_hdr->tsn); | |
374 | if (TSN_lt(ntsn, ltsn)) { | |
375 | list_add(new, pos->prev); | |
376 | done = 1; | |
377 | break; | |
378 | } | |
379 | } | |
380 | if (!done) | |
d808ad9a | 381 | list_add_tail(new, head); |
1da177e4 LT |
382 | } |
383 | ||
384 | /* Mark all the eligible packets on a transport for retransmission. */ | |
385 | void sctp_retransmit_mark(struct sctp_outq *q, | |
386 | struct sctp_transport *transport, | |
b6157d8e | 387 | __u8 reason) |
1da177e4 LT |
388 | { |
389 | struct list_head *lchunk, *ltemp; | |
390 | struct sctp_chunk *chunk; | |
391 | ||
392 | /* Walk through the specified transmitted queue. */ | |
393 | list_for_each_safe(lchunk, ltemp, &transport->transmitted) { | |
394 | chunk = list_entry(lchunk, struct sctp_chunk, | |
395 | transmitted_list); | |
396 | ||
397 | /* If the chunk is abandoned, move it to abandoned list. */ | |
398 | if (sctp_chunk_abandoned(chunk)) { | |
399 | list_del_init(lchunk); | |
400 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
401 | |
402 | /* If this chunk has not been previousely acked, | |
403 | * stop considering it 'outstanding'. Our peer | |
404 | * will most likely never see it since it will | |
405 | * not be retransmitted | |
406 | */ | |
407 | if (!chunk->tsn_gap_acked) { | |
31b02e15 VY |
408 | if (chunk->transport) |
409 | chunk->transport->flight_size -= | |
410 | sctp_data_size(chunk); | |
8c4a2d41 | 411 | q->outstanding_bytes -= sctp_data_size(chunk); |
a76c0adf | 412 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
8c4a2d41 | 413 | } |
1da177e4 LT |
414 | continue; |
415 | } | |
416 | ||
b6157d8e VY |
417 | /* If we are doing retransmission due to a timeout or pmtu |
418 | * discovery, only the chunks that are not yet acked should | |
419 | * be added to the retransmit queue. | |
1da177e4 | 420 | */ |
b6157d8e | 421 | if ((reason == SCTP_RTXR_FAST_RTX && |
c226ef9b | 422 | (chunk->fast_retransmit == SCTP_NEED_FRTX)) || |
b6157d8e | 423 | (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) { |
1da177e4 LT |
424 | /* RFC 2960 6.2.1 Processing a Received SACK |
425 | * | |
426 | * C) Any time a DATA chunk is marked for | |
427 | * retransmission (via either T3-rtx timer expiration | |
428 | * (Section 6.3.3) or via fast retransmit | |
429 | * (Section 7.2.4)), add the data size of those | |
430 | * chunks to the rwnd. | |
431 | */ | |
a76c0adf | 432 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
1da177e4 | 433 | q->outstanding_bytes -= sctp_data_size(chunk); |
31b02e15 VY |
434 | if (chunk->transport) |
435 | transport->flight_size -= sctp_data_size(chunk); | |
1da177e4 LT |
436 | |
437 | /* sctpimpguide-05 Section 2.8.2 | |
438 | * M5) If a T3-rtx timer expires, the | |
439 | * 'TSN.Missing.Report' of all affected TSNs is set | |
440 | * to 0. | |
441 | */ | |
442 | chunk->tsn_missing_report = 0; | |
443 | ||
444 | /* If a chunk that is being used for RTT measurement | |
445 | * has to be retransmitted, we cannot use this chunk | |
446 | * anymore for RTT measurements. Reset rto_pending so | |
447 | * that a new RTT measurement is started when a new | |
448 | * data chunk is sent. | |
449 | */ | |
450 | if (chunk->rtt_in_progress) { | |
451 | chunk->rtt_in_progress = 0; | |
452 | transport->rto_pending = 0; | |
453 | } | |
454 | ||
455 | /* Move the chunk to the retransmit queue. The chunks | |
456 | * on the retransmit queue are always kept in order. | |
457 | */ | |
458 | list_del_init(lchunk); | |
459 | sctp_insert_list(&q->retransmit, lchunk); | |
460 | } | |
461 | } | |
462 | ||
bb33381d DB |
463 | pr_debug("%s: transport:%p, reason:%d, cwnd:%d, ssthresh:%d, " |
464 | "flight_size:%d, pba:%d\n", __func__, transport, reason, | |
465 | transport->cwnd, transport->ssthresh, transport->flight_size, | |
466 | transport->partial_bytes_acked); | |
1da177e4 LT |
467 | } |
468 | ||
469 | /* Mark all the eligible packets on a transport for retransmission and force | |
470 | * one packet out. | |
471 | */ | |
472 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, | |
473 | sctp_retransmit_reason_t reason) | |
474 | { | |
b01a2407 | 475 | struct net *net = sock_net(q->asoc->base.sk); |
1da177e4 | 476 | int error = 0; |
1da177e4 LT |
477 | |
478 | switch(reason) { | |
479 | case SCTP_RTXR_T3_RTX: | |
b01a2407 | 480 | SCTP_INC_STATS(net, SCTP_MIB_T3_RETRANSMITS); |
1da177e4 LT |
481 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); |
482 | /* Update the retran path if the T3-rtx timer has expired for | |
483 | * the current retran path. | |
484 | */ | |
485 | if (transport == transport->asoc->peer.retran_path) | |
486 | sctp_assoc_update_retran_path(transport->asoc); | |
58fbbed4 NH |
487 | transport->asoc->rtx_data_chunks += |
488 | transport->asoc->unack_data; | |
1da177e4 LT |
489 | break; |
490 | case SCTP_RTXR_FAST_RTX: | |
b01a2407 | 491 | SCTP_INC_STATS(net, SCTP_MIB_FAST_RETRANSMITS); |
1da177e4 | 492 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); |
62aeaff5 | 493 | q->fast_rtx = 1; |
1da177e4 LT |
494 | break; |
495 | case SCTP_RTXR_PMTUD: | |
b01a2407 | 496 | SCTP_INC_STATS(net, SCTP_MIB_PMTUD_RETRANSMITS); |
1da177e4 | 497 | break; |
b6157d8e | 498 | case SCTP_RTXR_T1_RTX: |
b01a2407 | 499 | SCTP_INC_STATS(net, SCTP_MIB_T1_RETRANSMITS); |
58fbbed4 | 500 | transport->asoc->init_retries++; |
b6157d8e | 501 | break; |
ac0b0462 SS |
502 | default: |
503 | BUG(); | |
1da177e4 LT |
504 | } |
505 | ||
b6157d8e | 506 | sctp_retransmit_mark(q, transport, reason); |
1da177e4 LT |
507 | |
508 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, | |
509 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by | |
510 | * following the procedures outlined in C1 - C5. | |
511 | */ | |
8b750ce5 VY |
512 | if (reason == SCTP_RTXR_T3_RTX) |
513 | sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); | |
1da177e4 | 514 | |
8b750ce5 VY |
515 | /* Flush the queues only on timeout, since fast_rtx is only |
516 | * triggered during sack processing and the queue | |
517 | * will be flushed at the end. | |
518 | */ | |
519 | if (reason != SCTP_RTXR_FAST_RTX) | |
520 | error = sctp_outq_flush(q, /* rtx_timeout */ 1); | |
1da177e4 LT |
521 | |
522 | if (error) | |
523 | q->asoc->base.sk->sk_err = -error; | |
524 | } | |
525 | ||
526 | /* | |
527 | * Transmit DATA chunks on the retransmit queue. Upon return from | |
528 | * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which | |
529 | * need to be transmitted by the caller. | |
530 | * We assume that pkt->transport has already been set. | |
531 | * | |
532 | * The return value is a normal kernel error return value. | |
533 | */ | |
534 | static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, | |
535 | int rtx_timeout, int *start_timer) | |
536 | { | |
537 | struct list_head *lqueue; | |
1da177e4 LT |
538 | struct sctp_transport *transport = pkt->transport; |
539 | sctp_xmit_t status; | |
540 | struct sctp_chunk *chunk, *chunk1; | |
62aeaff5 | 541 | int fast_rtx; |
1da177e4 | 542 | int error = 0; |
62aeaff5 | 543 | int timer = 0; |
8b750ce5 | 544 | int done = 0; |
1da177e4 | 545 | |
1da177e4 | 546 | lqueue = &q->retransmit; |
62aeaff5 | 547 | fast_rtx = q->fast_rtx; |
1da177e4 | 548 | |
8b750ce5 VY |
549 | /* This loop handles time-out retransmissions, fast retransmissions, |
550 | * and retransmissions due to opening of whindow. | |
551 | * | |
552 | * RFC 2960 6.3.3 Handle T3-rtx Expiration | |
1da177e4 LT |
553 | * |
554 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
555 | * outstanding DATA chunks for the address for which the | |
556 | * T3-rtx has expired will fit into a single packet, subject | |
557 | * to the MTU constraint for the path corresponding to the | |
558 | * destination transport address to which the retransmission | |
559 | * is being sent (this may be different from the address for | |
560 | * which the timer expires [see Section 6.4]). Call this value | |
561 | * K. Bundle and retransmit those K DATA chunks in a single | |
562 | * packet to the destination endpoint. | |
563 | * | |
564 | * [Just to be painfully clear, if we are retransmitting | |
565 | * because a timeout just happened, we should send only ONE | |
566 | * packet of retransmitted data.] | |
8b750ce5 VY |
567 | * |
568 | * For fast retransmissions we also send only ONE packet. However, | |
569 | * if we are just flushing the queue due to open window, we'll | |
570 | * try to send as much as possible. | |
1da177e4 | 571 | */ |
8b750ce5 | 572 | list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { |
4c6a6f42 WY |
573 | /* If the chunk is abandoned, move it to abandoned list. */ |
574 | if (sctp_chunk_abandoned(chunk)) { | |
575 | list_del_init(&chunk->transmitted_list); | |
576 | sctp_insert_list(&q->abandoned, | |
577 | &chunk->transmitted_list); | |
578 | continue; | |
579 | } | |
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) { | |
54a27924 WY |
587 | list_move_tail(&chunk->transmitted_list, |
588 | &transport->transmitted); | |
1da177e4 LT |
589 | continue; |
590 | } | |
591 | ||
8b750ce5 VY |
592 | /* If we are doing fast retransmit, ignore non-fast_rtransmit |
593 | * chunks | |
594 | */ | |
595 | if (fast_rtx && !chunk->fast_retransmit) | |
596 | continue; | |
597 | ||
bc4f841a | 598 | redo: |
1da177e4 LT |
599 | /* Attempt to append this chunk to the packet. */ |
600 | status = sctp_packet_append_chunk(pkt, chunk); | |
601 | ||
602 | switch (status) { | |
603 | case SCTP_XMIT_PMTU_FULL: | |
bc4f841a WY |
604 | if (!pkt->has_data && !pkt->has_cookie_echo) { |
605 | /* If this packet did not contain DATA then | |
606 | * retransmission did not happen, so do it | |
607 | * again. We'll ignore the error here since | |
608 | * control chunks are already freed so there | |
609 | * is nothing we can do. | |
610 | */ | |
611 | sctp_packet_transmit(pkt); | |
612 | goto redo; | |
613 | } | |
614 | ||
1da177e4 | 615 | /* Send this packet. */ |
62aeaff5 | 616 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
617 | |
618 | /* If we are retransmitting, we should only | |
619 | * send a single packet. | |
f246a7b7 | 620 | * Otherwise, try appending this chunk again. |
1da177e4 | 621 | */ |
8b750ce5 VY |
622 | if (rtx_timeout || fast_rtx) |
623 | done = 1; | |
f246a7b7 VY |
624 | else |
625 | goto redo; | |
1da177e4 | 626 | |
8b750ce5 | 627 | /* Bundle next chunk in the next round. */ |
1da177e4 LT |
628 | break; |
629 | ||
630 | case SCTP_XMIT_RWND_FULL: | |
d808ad9a | 631 | /* Send this packet. */ |
62aeaff5 | 632 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
633 | |
634 | /* Stop sending DATA as there is no more room | |
635 | * at the receiver. | |
636 | */ | |
8b750ce5 | 637 | done = 1; |
1da177e4 LT |
638 | break; |
639 | ||
640 | case SCTP_XMIT_NAGLE_DELAY: | |
d808ad9a | 641 | /* Send this packet. */ |
62aeaff5 | 642 | error = sctp_packet_transmit(pkt); |
1da177e4 LT |
643 | |
644 | /* Stop sending DATA because of nagle delay. */ | |
8b750ce5 | 645 | done = 1; |
1da177e4 LT |
646 | break; |
647 | ||
648 | default: | |
649 | /* The append was successful, so add this chunk to | |
650 | * the transmitted list. | |
651 | */ | |
54a27924 WY |
652 | list_move_tail(&chunk->transmitted_list, |
653 | &transport->transmitted); | |
1da177e4 | 654 | |
d808ad9a | 655 | /* Mark the chunk as ineligible for fast retransmit |
1da177e4 LT |
656 | * after it is retransmitted. |
657 | */ | |
c226ef9b NH |
658 | if (chunk->fast_retransmit == SCTP_NEED_FRTX) |
659 | chunk->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 | 660 | |
1da177e4 | 661 | q->empty = 0; |
196d6759 | 662 | q->asoc->stats.rtxchunks++; |
1da177e4 | 663 | break; |
3ff50b79 | 664 | } |
1da177e4 | 665 | |
62aeaff5 VY |
666 | /* Set the timer if there were no errors */ |
667 | if (!error && !timer) | |
668 | timer = 1; | |
669 | ||
8b750ce5 VY |
670 | if (done) |
671 | break; | |
672 | } | |
673 | ||
674 | /* If we are here due to a retransmit timeout or a fast | |
675 | * retransmit and if there are any chunks left in the retransmit | |
676 | * queue that could not fit in the PMTU sized packet, they need | |
677 | * to be marked as ineligible for a subsequent fast retransmit. | |
678 | */ | |
679 | if (rtx_timeout || fast_rtx) { | |
680 | list_for_each_entry(chunk1, lqueue, transmitted_list) { | |
c226ef9b NH |
681 | if (chunk1->fast_retransmit == SCTP_NEED_FRTX) |
682 | chunk1->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 LT |
683 | } |
684 | } | |
685 | ||
62aeaff5 VY |
686 | *start_timer = timer; |
687 | ||
688 | /* Clear fast retransmit hint */ | |
689 | if (fast_rtx) | |
690 | q->fast_rtx = 0; | |
691 | ||
1da177e4 LT |
692 | return error; |
693 | } | |
694 | ||
695 | /* Cork the outqueue so queued chunks are really queued. */ | |
696 | int sctp_outq_uncork(struct sctp_outq *q) | |
697 | { | |
7d54dc68 | 698 | if (q->cork) |
1da177e4 | 699 | q->cork = 0; |
dacda32e DB |
700 | |
701 | return sctp_outq_flush(q, 0); | |
1da177e4 LT |
702 | } |
703 | ||
2e3216cd | 704 | |
1da177e4 LT |
705 | /* |
706 | * Try to flush an outqueue. | |
707 | * | |
708 | * Description: Send everything in q which we legally can, subject to | |
709 | * congestion limitations. | |
710 | * * Note: This function can be called from multiple contexts so appropriate | |
711 | * locking concerns must be made. Today we use the sock lock to protect | |
712 | * this function. | |
713 | */ | |
abd0b198 | 714 | static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) |
1da177e4 LT |
715 | { |
716 | struct sctp_packet *packet; | |
717 | struct sctp_packet singleton; | |
718 | struct sctp_association *asoc = q->asoc; | |
719 | __u16 sport = asoc->base.bind_addr.port; | |
720 | __u16 dport = asoc->peer.port; | |
721 | __u32 vtag = asoc->peer.i.init_tag; | |
1da177e4 LT |
722 | struct sctp_transport *transport = NULL; |
723 | struct sctp_transport *new_transport; | |
79af02c2 | 724 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
725 | sctp_xmit_t status; |
726 | int error = 0; | |
727 | int start_timer = 0; | |
2e3216cd | 728 | int one_packet = 0; |
1da177e4 LT |
729 | |
730 | /* These transports have chunks to send. */ | |
731 | struct list_head transport_list; | |
732 | struct list_head *ltransport; | |
733 | ||
734 | INIT_LIST_HEAD(&transport_list); | |
735 | packet = NULL; | |
736 | ||
737 | /* | |
738 | * 6.10 Bundling | |
739 | * ... | |
740 | * When bundling control chunks with DATA chunks, an | |
741 | * endpoint MUST place control chunks first in the outbound | |
742 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
743 | * within a SCTP packet in increasing order of TSN. | |
744 | * ... | |
745 | */ | |
746 | ||
79af02c2 | 747 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
8a07eb0a MH |
748 | /* RFC 5061, 5.3 |
749 | * F1) This means that until such time as the ASCONF | |
750 | * containing the add is acknowledged, the sender MUST | |
751 | * NOT use the new IP address as a source for ANY SCTP | |
752 | * packet except on carrying an ASCONF Chunk. | |
753 | */ | |
754 | if (asoc->src_out_of_asoc_ok && | |
755 | chunk->chunk_hdr->type != SCTP_CID_ASCONF) | |
756 | continue; | |
757 | ||
79af02c2 DM |
758 | list_del_init(&chunk->list); |
759 | ||
1da177e4 LT |
760 | /* Pick the right transport to use. */ |
761 | new_transport = chunk->transport; | |
762 | ||
763 | if (!new_transport) { | |
a08de64d VY |
764 | /* |
765 | * If we have a prior transport pointer, see if | |
766 | * the destination address of the chunk | |
767 | * matches the destination address of the | |
768 | * current transport. If not a match, then | |
769 | * try to look up the transport with a given | |
770 | * destination address. We do this because | |
771 | * after processing ASCONFs, we may have new | |
772 | * transports created. | |
773 | */ | |
774 | if (transport && | |
775 | sctp_cmp_addr_exact(&chunk->dest, | |
776 | &transport->ipaddr)) | |
777 | new_transport = transport; | |
778 | else | |
779 | new_transport = sctp_assoc_lookup_paddr(asoc, | |
780 | &chunk->dest); | |
781 | ||
782 | /* if we still don't have a new transport, then | |
783 | * use the current active path. | |
784 | */ | |
785 | if (!new_transport) | |
786 | new_transport = asoc->peer.active_path; | |
ad8fec17 | 787 | } else if ((new_transport->state == SCTP_INACTIVE) || |
5aa93bcf NH |
788 | (new_transport->state == SCTP_UNCONFIRMED) || |
789 | (new_transport->state == SCTP_PF)) { | |
3f7a87d2 FF |
790 | /* If the chunk is Heartbeat or Heartbeat Ack, |
791 | * send it to chunk->transport, even if it's | |
1da177e4 LT |
792 | * inactive. |
793 | * | |
794 | * 3.3.6 Heartbeat Acknowledgement: | |
d808ad9a | 795 | * ... |
1da177e4 LT |
796 | * A HEARTBEAT ACK is always sent to the source IP |
797 | * address of the IP datagram containing the | |
798 | * HEARTBEAT chunk to which this ack is responding. | |
d808ad9a | 799 | * ... |
a08de64d VY |
800 | * |
801 | * ASCONF_ACKs also must be sent to the source. | |
1da177e4 LT |
802 | */ |
803 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && | |
a08de64d VY |
804 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK && |
805 | chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK) | |
1da177e4 LT |
806 | new_transport = asoc->peer.active_path; |
807 | } | |
808 | ||
809 | /* Are we switching transports? | |
810 | * Take care of transport locks. | |
811 | */ | |
812 | if (new_transport != transport) { | |
813 | transport = new_transport; | |
814 | if (list_empty(&transport->send_ready)) { | |
815 | list_add_tail(&transport->send_ready, | |
816 | &transport_list); | |
817 | } | |
818 | packet = &transport->packet; | |
819 | sctp_packet_config(packet, vtag, | |
820 | asoc->peer.ecn_capable); | |
821 | } | |
822 | ||
823 | switch (chunk->chunk_hdr->type) { | |
824 | /* | |
825 | * 6.10 Bundling | |
826 | * ... | |
827 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
828 | * COMPLETE with any other chunks. [Send them immediately.] | |
829 | */ | |
830 | case SCTP_CID_INIT: | |
831 | case SCTP_CID_INIT_ACK: | |
832 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
833 | sctp_packet_init(&singleton, transport, sport, dport); | |
834 | sctp_packet_config(&singleton, vtag, 0); | |
835 | sctp_packet_append_chunk(&singleton, chunk); | |
836 | error = sctp_packet_transmit(&singleton); | |
837 | if (error < 0) | |
838 | return error; | |
839 | break; | |
840 | ||
841 | case SCTP_CID_ABORT: | |
f4ad85ca GJ |
842 | if (sctp_test_T_bit(chunk)) { |
843 | packet->vtag = asoc->c.my_vtag; | |
844 | } | |
2e3216cd VY |
845 | /* The following chunks are "response" chunks, i.e. |
846 | * they are generated in response to something we | |
847 | * received. If we are sending these, then we can | |
848 | * send only 1 packet containing these chunks. | |
849 | */ | |
1da177e4 | 850 | case SCTP_CID_HEARTBEAT_ACK: |
1da177e4 | 851 | case SCTP_CID_SHUTDOWN_ACK: |
1da177e4 | 852 | case SCTP_CID_COOKIE_ACK: |
2e3216cd VY |
853 | case SCTP_CID_COOKIE_ECHO: |
854 | case SCTP_CID_ERROR: | |
1da177e4 | 855 | case SCTP_CID_ECN_CWR: |
1da177e4 | 856 | case SCTP_CID_ASCONF_ACK: |
2e3216cd | 857 | one_packet = 1; |
25985edc | 858 | /* Fall through */ |
2e3216cd VY |
859 | |
860 | case SCTP_CID_SACK: | |
861 | case SCTP_CID_HEARTBEAT: | |
862 | case SCTP_CID_SHUTDOWN: | |
863 | case SCTP_CID_ECN_ECNE: | |
864 | case SCTP_CID_ASCONF: | |
1da177e4 | 865 | case SCTP_CID_FWD_TSN: |
2e3216cd VY |
866 | status = sctp_packet_transmit_chunk(packet, chunk, |
867 | one_packet); | |
868 | if (status != SCTP_XMIT_OK) { | |
869 | /* put the chunk back */ | |
870 | list_add(&chunk->list, &q->control_chunk_list); | |
196d6759 MB |
871 | } else { |
872 | asoc->stats.octrlchunks++; | |
bd69b981 WY |
873 | /* PR-SCTP C5) If a FORWARD TSN is sent, the |
874 | * sender MUST assure that at least one T3-rtx | |
875 | * timer is running. | |
876 | */ | |
196d6759 MB |
877 | if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) |
878 | sctp_transport_reset_timers(transport); | |
2e3216cd | 879 | } |
1da177e4 LT |
880 | break; |
881 | ||
882 | default: | |
883 | /* We built a chunk with an illegal type! */ | |
884 | BUG(); | |
3ff50b79 | 885 | } |
1da177e4 LT |
886 | } |
887 | ||
8a07eb0a MH |
888 | if (q->asoc->src_out_of_asoc_ok) |
889 | goto sctp_flush_out; | |
890 | ||
1da177e4 LT |
891 | /* Is it OK to send data chunks? */ |
892 | switch (asoc->state) { | |
893 | case SCTP_STATE_COOKIE_ECHOED: | |
894 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
895 | * chunk. | |
896 | */ | |
897 | if (!packet || !packet->has_cookie_echo) | |
898 | break; | |
899 | ||
900 | /* fallthru */ | |
901 | case SCTP_STATE_ESTABLISHED: | |
902 | case SCTP_STATE_SHUTDOWN_PENDING: | |
903 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
904 | /* | |
905 | * RFC 2960 6.1 Transmission of DATA Chunks | |
906 | * | |
907 | * C) When the time comes for the sender to transmit, | |
908 | * before sending new DATA chunks, the sender MUST | |
909 | * first transmit any outstanding DATA chunks which | |
910 | * are marked for retransmission (limited by the | |
911 | * current cwnd). | |
912 | */ | |
913 | if (!list_empty(&q->retransmit)) { | |
f207c050 MH |
914 | if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED) |
915 | goto sctp_flush_out; | |
1da177e4 LT |
916 | if (transport == asoc->peer.retran_path) |
917 | goto retran; | |
918 | ||
919 | /* Switch transports & prepare the packet. */ | |
920 | ||
921 | transport = asoc->peer.retran_path; | |
922 | ||
923 | if (list_empty(&transport->send_ready)) { | |
924 | list_add_tail(&transport->send_ready, | |
925 | &transport_list); | |
926 | } | |
927 | ||
928 | packet = &transport->packet; | |
929 | sctp_packet_config(packet, vtag, | |
930 | asoc->peer.ecn_capable); | |
931 | retran: | |
932 | error = sctp_outq_flush_rtx(q, packet, | |
933 | rtx_timeout, &start_timer); | |
934 | ||
935 | if (start_timer) | |
d9efc223 | 936 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
937 | |
938 | /* This can happen on COOKIE-ECHO resend. Only | |
939 | * one chunk can get bundled with a COOKIE-ECHO. | |
940 | */ | |
941 | if (packet->has_cookie_echo) | |
942 | goto sctp_flush_out; | |
943 | ||
944 | /* Don't send new data if there is still data | |
945 | * waiting to retransmit. | |
946 | */ | |
947 | if (!list_empty(&q->retransmit)) | |
948 | goto sctp_flush_out; | |
949 | } | |
950 | ||
46d5a808 VY |
951 | /* Apply Max.Burst limitation to the current transport in |
952 | * case it will be used for new data. We are going to | |
953 | * rest it before we return, but we want to apply the limit | |
954 | * to the currently queued data. | |
955 | */ | |
956 | if (transport) | |
957 | sctp_transport_burst_limited(transport); | |
958 | ||
1da177e4 | 959 | /* Finally, transmit new packets. */ |
1da177e4 LT |
960 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
961 | /* RFC 2960 6.5 Every DATA chunk MUST carry a valid | |
962 | * stream identifier. | |
963 | */ | |
964 | if (chunk->sinfo.sinfo_stream >= | |
965 | asoc->c.sinit_num_ostreams) { | |
966 | ||
967 | /* Mark as failed send. */ | |
968 | sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); | |
969 | sctp_chunk_free(chunk); | |
970 | continue; | |
971 | } | |
972 | ||
973 | /* Has this chunk expired? */ | |
974 | if (sctp_chunk_abandoned(chunk)) { | |
975 | sctp_chunk_fail(chunk, 0); | |
976 | sctp_chunk_free(chunk); | |
977 | continue; | |
978 | } | |
979 | ||
980 | /* If there is a specified transport, use it. | |
981 | * Otherwise, we want to use the active path. | |
982 | */ | |
983 | new_transport = chunk->transport; | |
3f7a87d2 | 984 | if (!new_transport || |
ad8fec17 | 985 | ((new_transport->state == SCTP_INACTIVE) || |
5aa93bcf NH |
986 | (new_transport->state == SCTP_UNCONFIRMED) || |
987 | (new_transport->state == SCTP_PF))) | |
1da177e4 | 988 | new_transport = asoc->peer.active_path; |
f207c050 MH |
989 | if (new_transport->state == SCTP_UNCONFIRMED) |
990 | continue; | |
1da177e4 LT |
991 | |
992 | /* Change packets if necessary. */ | |
993 | if (new_transport != transport) { | |
994 | transport = new_transport; | |
995 | ||
996 | /* Schedule to have this transport's | |
997 | * packet flushed. | |
998 | */ | |
999 | if (list_empty(&transport->send_ready)) { | |
1000 | list_add_tail(&transport->send_ready, | |
1001 | &transport_list); | |
1002 | } | |
1003 | ||
1004 | packet = &transport->packet; | |
1005 | sctp_packet_config(packet, vtag, | |
1006 | asoc->peer.ecn_capable); | |
46d5a808 VY |
1007 | /* We've switched transports, so apply the |
1008 | * Burst limit to the new transport. | |
1009 | */ | |
1010 | sctp_transport_burst_limited(transport); | |
1da177e4 LT |
1011 | } |
1012 | ||
bb33381d DB |
1013 | pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p " |
1014 | "skb->users:%d\n", | |
1015 | __func__, q, chunk, chunk && chunk->chunk_hdr ? | |
1016 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
1017 | "illegal chunk", ntohl(chunk->subh.data_hdr->tsn), | |
1018 | chunk->skb ? chunk->skb->head : NULL, chunk->skb ? | |
1019 | atomic_read(&chunk->skb->users) : -1); | |
1da177e4 LT |
1020 | |
1021 | /* Add the chunk to the packet. */ | |
2e3216cd | 1022 | status = sctp_packet_transmit_chunk(packet, chunk, 0); |
1da177e4 LT |
1023 | |
1024 | switch (status) { | |
1025 | case SCTP_XMIT_PMTU_FULL: | |
1026 | case SCTP_XMIT_RWND_FULL: | |
1027 | case SCTP_XMIT_NAGLE_DELAY: | |
1028 | /* We could not append this chunk, so put | |
1029 | * the chunk back on the output queue. | |
1030 | */ | |
bb33381d DB |
1031 | pr_debug("%s: could not transmit tsn:0x%x, status:%d\n", |
1032 | __func__, ntohl(chunk->subh.data_hdr->tsn), | |
1033 | status); | |
1034 | ||
1da177e4 LT |
1035 | sctp_outq_head_data(q, chunk); |
1036 | goto sctp_flush_out; | |
1037 | break; | |
1038 | ||
1039 | case SCTP_XMIT_OK: | |
b93d6471 WY |
1040 | /* The sender is in the SHUTDOWN-PENDING state, |
1041 | * The sender MAY set the I-bit in the DATA | |
1042 | * chunk header. | |
1043 | */ | |
1044 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) | |
1045 | chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; | |
196d6759 MB |
1046 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) |
1047 | asoc->stats.ouodchunks++; | |
1048 | else | |
1049 | asoc->stats.oodchunks++; | |
b93d6471 | 1050 | |
1da177e4 LT |
1051 | break; |
1052 | ||
1053 | default: | |
1054 | BUG(); | |
1055 | } | |
1056 | ||
d808ad9a | 1057 | /* BUG: We assume that the sctp_packet_transmit() |
1da177e4 LT |
1058 | * call below will succeed all the time and add the |
1059 | * chunk to the transmitted list and restart the | |
1060 | * timers. | |
1061 | * It is possible that the call can fail under OOM | |
1062 | * conditions. | |
1063 | * | |
1064 | * Is this really a problem? Won't this behave | |
1065 | * like a lost TSN? | |
1066 | */ | |
1067 | list_add_tail(&chunk->transmitted_list, | |
1068 | &transport->transmitted); | |
1069 | ||
d9efc223 | 1070 | sctp_transport_reset_timers(transport); |
1da177e4 LT |
1071 | |
1072 | q->empty = 0; | |
1073 | ||
1074 | /* Only let one DATA chunk get bundled with a | |
1075 | * COOKIE-ECHO chunk. | |
1076 | */ | |
1077 | if (packet->has_cookie_echo) | |
1078 | goto sctp_flush_out; | |
1079 | } | |
1080 | break; | |
1081 | ||
1082 | default: | |
1083 | /* Do nothing. */ | |
1084 | break; | |
1085 | } | |
1086 | ||
1087 | sctp_flush_out: | |
1088 | ||
1089 | /* Before returning, examine all the transports touched in | |
1090 | * this call. Right now, we bluntly force clear all the | |
1091 | * transports. Things might change after we implement Nagle. | |
1092 | * But such an examination is still required. | |
1093 | * | |
1094 | * --xguo | |
1095 | */ | |
1096 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) { | |
1097 | struct sctp_transport *t = list_entry(ltransport, | |
1098 | struct sctp_transport, | |
1099 | send_ready); | |
1100 | packet = &t->packet; | |
1101 | if (!sctp_packet_empty(packet)) | |
1102 | error = sctp_packet_transmit(packet); | |
46d5a808 VY |
1103 | |
1104 | /* Clear the burst limited state, if any */ | |
1105 | sctp_transport_burst_reset(t); | |
1da177e4 LT |
1106 | } |
1107 | ||
1108 | return error; | |
1109 | } | |
1110 | ||
1111 | /* Update unack_data based on the incoming SACK chunk */ | |
1112 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
1113 | struct sctp_sackhdr *sack) | |
1114 | { | |
1115 | sctp_sack_variable_t *frags; | |
1116 | __u16 unack_data; | |
1117 | int i; | |
1118 | ||
1119 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
1120 | ||
1121 | frags = sack->variable; | |
1122 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
1123 | unack_data -= ((ntohs(frags[i].gab.end) - | |
1124 | ntohs(frags[i].gab.start) + 1)); | |
1125 | } | |
1126 | ||
1127 | assoc->unack_data = unack_data; | |
1128 | } | |
1129 | ||
1da177e4 LT |
1130 | /* This is where we REALLY process a SACK. |
1131 | * | |
1132 | * Process the SACK against the outqueue. Mostly, this just frees | |
1133 | * things off the transmitted queue. | |
1134 | */ | |
edfee033 | 1135 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk) |
1da177e4 LT |
1136 | { |
1137 | struct sctp_association *asoc = q->asoc; | |
edfee033 | 1138 | struct sctp_sackhdr *sack = chunk->subh.sack_hdr; |
1da177e4 LT |
1139 | struct sctp_transport *transport; |
1140 | struct sctp_chunk *tchunk = NULL; | |
9dbc15f0 | 1141 | struct list_head *lchunk, *transport_list, *temp; |
1da177e4 LT |
1142 | sctp_sack_variable_t *frags = sack->variable; |
1143 | __u32 sack_ctsn, ctsn, tsn; | |
1144 | __u32 highest_tsn, highest_new_tsn; | |
1145 | __u32 sack_a_rwnd; | |
95c96174 | 1146 | unsigned int outstanding; |
1da177e4 LT |
1147 | struct sctp_transport *primary = asoc->peer.primary_path; |
1148 | int count_of_newacks = 0; | |
2cd9b822 | 1149 | int gap_ack_blocks; |
ea862c8d | 1150 | u8 accum_moved = 0; |
1da177e4 LT |
1151 | |
1152 | /* Grab the association's destination address list. */ | |
1153 | transport_list = &asoc->peer.transport_addr_list; | |
1154 | ||
1155 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
2cd9b822 | 1156 | gap_ack_blocks = ntohs(sack->num_gap_ack_blocks); |
196d6759 | 1157 | asoc->stats.gapcnt += gap_ack_blocks; |
1da177e4 LT |
1158 | /* |
1159 | * SFR-CACC algorithm: | |
1160 | * On receipt of a SACK the sender SHOULD execute the | |
1161 | * following statements. | |
1162 | * | |
1163 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1164 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1165 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1166 | * all destinations. | |
1da177e4 LT |
1167 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
1168 | * is set the receiver of the SACK MUST take the following actions: | |
1169 | * | |
1170 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1171 | * addresses. | |
ab5216a5 VY |
1172 | * |
1173 | * Only bother if changeover_active is set. Otherwise, this is | |
1174 | * totally suboptimal to do on every SACK. | |
1da177e4 | 1175 | */ |
ab5216a5 VY |
1176 | if (primary->cacc.changeover_active) { |
1177 | u8 clear_cycling = 0; | |
1178 | ||
1179 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1180 | primary->cacc.changeover_active = 0; | |
1181 | clear_cycling = 1; | |
1182 | } | |
1183 | ||
1184 | if (clear_cycling || gap_ack_blocks) { | |
1185 | list_for_each_entry(transport, transport_list, | |
1186 | transports) { | |
1187 | if (clear_cycling) | |
1188 | transport->cacc.cycling_changeover = 0; | |
1189 | if (gap_ack_blocks) | |
1190 | transport->cacc.cacc_saw_newack = 0; | |
1191 | } | |
1da177e4 LT |
1192 | } |
1193 | } | |
1194 | ||
1195 | /* Get the highest TSN in the sack. */ | |
1196 | highest_tsn = sack_ctsn; | |
2cd9b822 VY |
1197 | if (gap_ack_blocks) |
1198 | highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); | |
1da177e4 | 1199 | |
bfa0d984 | 1200 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) |
1da177e4 | 1201 | asoc->highest_sacked = highest_tsn; |
1da177e4 | 1202 | |
bfa0d984 | 1203 | highest_new_tsn = sack_ctsn; |
2cd9b822 | 1204 | |
1da177e4 LT |
1205 | /* Run through the retransmit queue. Credit bytes received |
1206 | * and free those chunks that we can. | |
1207 | */ | |
edfee033 | 1208 | sctp_check_transmitted(q, &q->retransmit, NULL, NULL, sack, &highest_new_tsn); |
1da177e4 LT |
1209 | |
1210 | /* Run through the transmitted queue. | |
1211 | * Credit bytes received and free those chunks which we can. | |
1212 | * | |
1213 | * This is a MASSIVE candidate for optimization. | |
1214 | */ | |
9dbc15f0 | 1215 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 | 1216 | sctp_check_transmitted(q, &transport->transmitted, |
edfee033 ND |
1217 | transport, &chunk->source, sack, |
1218 | &highest_new_tsn); | |
1da177e4 LT |
1219 | /* |
1220 | * SFR-CACC algorithm: | |
1221 | * C) Let count_of_newacks be the number of | |
1222 | * destinations for which cacc_saw_newack is set. | |
1223 | */ | |
1224 | if (transport->cacc.cacc_saw_newack) | |
1225 | count_of_newacks ++; | |
1226 | } | |
1227 | ||
ea862c8d VY |
1228 | /* Move the Cumulative TSN Ack Point if appropriate. */ |
1229 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) { | |
1230 | asoc->ctsn_ack_point = sack_ctsn; | |
1231 | accum_moved = 1; | |
1232 | } | |
1233 | ||
2cd9b822 | 1234 | if (gap_ack_blocks) { |
ea862c8d VY |
1235 | |
1236 | if (asoc->fast_recovery && accum_moved) | |
1237 | highest_new_tsn = highest_tsn; | |
1238 | ||
2cd9b822 VY |
1239 | list_for_each_entry(transport, transport_list, transports) |
1240 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1241 | highest_new_tsn, count_of_newacks); | |
1da177e4 LT |
1242 | } |
1243 | ||
1da177e4 LT |
1244 | /* Update unack_data field in the assoc. */ |
1245 | sctp_sack_update_unack_data(asoc, sack); | |
1246 | ||
1247 | ctsn = asoc->ctsn_ack_point; | |
1248 | ||
1249 | /* Throw away stuff rotting on the sack queue. */ | |
1250 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1251 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1252 | transmitted_list); | |
1253 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
5f9646c3 VY |
1254 | if (TSN_lte(tsn, ctsn)) { |
1255 | list_del_init(&tchunk->transmitted_list); | |
1da177e4 | 1256 | sctp_chunk_free(tchunk); |
5f9646c3 | 1257 | } |
1da177e4 LT |
1258 | } |
1259 | ||
1260 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1261 | * number of bytes still outstanding after processing the | |
1262 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1263 | */ | |
1264 | ||
1265 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
1266 | outstanding = q->outstanding_bytes; | |
1267 | ||
1268 | if (outstanding < sack_a_rwnd) | |
1269 | sack_a_rwnd -= outstanding; | |
1270 | else | |
1271 | sack_a_rwnd = 0; | |
1272 | ||
1273 | asoc->peer.rwnd = sack_a_rwnd; | |
1274 | ||
1275 | sctp_generate_fwdtsn(q, sack_ctsn); | |
1276 | ||
bb33381d DB |
1277 | pr_debug("%s: sack cumulative tsn ack:0x%x\n", __func__, sack_ctsn); |
1278 | pr_debug("%s: cumulative tsn ack of assoc:%p is 0x%x, " | |
1279 | "advertised peer ack point:0x%x\n", __func__, asoc, ctsn, | |
1280 | asoc->adv_peer_ack_point); | |
1da177e4 LT |
1281 | |
1282 | /* See if all chunks are acked. | |
1283 | * Make sure the empty queue handler will get run later. | |
1284 | */ | |
79af02c2 | 1285 | q->empty = (list_empty(&q->out_chunk_list) && |
79af02c2 | 1286 | list_empty(&q->retransmit)); |
1da177e4 LT |
1287 | if (!q->empty) |
1288 | goto finish; | |
1289 | ||
9dbc15f0 | 1290 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 LT |
1291 | q->empty = q->empty && list_empty(&transport->transmitted); |
1292 | if (!q->empty) | |
1293 | goto finish; | |
1294 | } | |
1295 | ||
bb33381d | 1296 | pr_debug("%s: sack queue is empty\n", __func__); |
1da177e4 LT |
1297 | finish: |
1298 | return q->empty; | |
1299 | } | |
1300 | ||
1301 | /* Is the outqueue empty? */ | |
1302 | int sctp_outq_is_empty(const struct sctp_outq *q) | |
1303 | { | |
1304 | return q->empty; | |
1305 | } | |
1306 | ||
1307 | /******************************************************************** | |
1308 | * 2nd Level Abstractions | |
1309 | ********************************************************************/ | |
1310 | ||
1311 | /* Go through a transport's transmitted list or the association's retransmit | |
1312 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1313 | * The retransmit list will not have an associated transport. | |
1314 | * | |
1315 | * I added coherent debug information output. --xguo | |
1316 | * | |
1317 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1318 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1319 | * KEPT TSN6-TSN7, etc. | |
1320 | */ | |
1321 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1322 | struct list_head *transmitted_queue, | |
1323 | struct sctp_transport *transport, | |
edfee033 | 1324 | union sctp_addr *saddr, |
1da177e4 | 1325 | struct sctp_sackhdr *sack, |
bfa0d984 | 1326 | __u32 *highest_new_tsn_in_sack) |
1da177e4 LT |
1327 | { |
1328 | struct list_head *lchunk; | |
1329 | struct sctp_chunk *tchunk; | |
1330 | struct list_head tlist; | |
1331 | __u32 tsn; | |
1332 | __u32 sack_ctsn; | |
1333 | __u32 rtt; | |
1334 | __u8 restart_timer = 0; | |
1335 | int bytes_acked = 0; | |
31b02e15 | 1336 | int migrate_bytes = 0; |
8c2f414a | 1337 | bool forward_progress = false; |
1da177e4 | 1338 | |
1da177e4 LT |
1339 | sack_ctsn = ntohl(sack->cum_tsn_ack); |
1340 | ||
1341 | INIT_LIST_HEAD(&tlist); | |
1342 | ||
1343 | /* The while loop will skip empty transmitted queues. */ | |
1344 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1345 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1346 | transmitted_list); | |
1347 | ||
1348 | if (sctp_chunk_abandoned(tchunk)) { | |
1349 | /* Move the chunk to abandoned list. */ | |
1350 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
1351 | |
1352 | /* If this chunk has not been acked, stop | |
1353 | * considering it as 'outstanding'. | |
1354 | */ | |
1355 | if (!tchunk->tsn_gap_acked) { | |
31b02e15 VY |
1356 | if (tchunk->transport) |
1357 | tchunk->transport->flight_size -= | |
1358 | sctp_data_size(tchunk); | |
8c4a2d41 VY |
1359 | q->outstanding_bytes -= sctp_data_size(tchunk); |
1360 | } | |
1da177e4 LT |
1361 | continue; |
1362 | } | |
1363 | ||
1364 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1365 | if (sctp_acked(sack, tsn)) { | |
1366 | /* If this queue is the retransmit queue, the | |
1367 | * retransmit timer has already reclaimed | |
1368 | * the outstanding bytes for this chunk, so only | |
1369 | * count bytes associated with a transport. | |
1370 | */ | |
1371 | if (transport) { | |
1372 | /* If this chunk is being used for RTT | |
1373 | * measurement, calculate the RTT and update | |
1374 | * the RTO using this value. | |
1375 | * | |
1376 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1377 | * MUST NOT be made using packets that were | |
1378 | * retransmitted (and thus for which it is | |
1379 | * ambiguous whether the reply was for the | |
1380 | * first instance of the packet or a later | |
1381 | * instance). | |
1382 | */ | |
d808ad9a | 1383 | if (!tchunk->tsn_gap_acked && |
1da177e4 | 1384 | tchunk->rtt_in_progress) { |
4c9f5d53 | 1385 | tchunk->rtt_in_progress = 0; |
1da177e4 LT |
1386 | rtt = jiffies - tchunk->sent_at; |
1387 | sctp_transport_update_rto(transport, | |
1388 | rtt); | |
1389 | } | |
1390 | } | |
31b02e15 VY |
1391 | |
1392 | /* If the chunk hasn't been marked as ACKED, | |
1393 | * mark it and account bytes_acked if the | |
1394 | * chunk had a valid transport (it will not | |
1395 | * have a transport if ASCONF had deleted it | |
1396 | * while DATA was outstanding). | |
1397 | */ | |
1398 | if (!tchunk->tsn_gap_acked) { | |
1399 | tchunk->tsn_gap_acked = 1; | |
bfa0d984 | 1400 | *highest_new_tsn_in_sack = tsn; |
31b02e15 VY |
1401 | bytes_acked += sctp_data_size(tchunk); |
1402 | if (!tchunk->transport) | |
1403 | migrate_bytes += sctp_data_size(tchunk); | |
8c2f414a | 1404 | forward_progress = true; |
31b02e15 VY |
1405 | } |
1406 | ||
d808ad9a | 1407 | if (TSN_lte(tsn, sack_ctsn)) { |
1da177e4 LT |
1408 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
1409 | * | |
1410 | * R3) Whenever a SACK is received | |
1411 | * that acknowledges the DATA chunk | |
1412 | * with the earliest outstanding TSN | |
1413 | * for that address, restart T3-rtx | |
1414 | * timer for that address with its | |
1415 | * current RTO. | |
1416 | */ | |
1417 | restart_timer = 1; | |
8c2f414a | 1418 | forward_progress = true; |
1da177e4 LT |
1419 | |
1420 | if (!tchunk->tsn_gap_acked) { | |
1da177e4 LT |
1421 | /* |
1422 | * SFR-CACC algorithm: | |
1423 | * 2) If the SACK contains gap acks | |
1424 | * and the flag CHANGEOVER_ACTIVE is | |
1425 | * set the receiver of the SACK MUST | |
1426 | * take the following action: | |
1427 | * | |
1428 | * B) For each TSN t being acked that | |
1429 | * has not been acked in any SACK so | |
1430 | * far, set cacc_saw_newack to 1 for | |
1431 | * the destination that the TSN was | |
1432 | * sent to. | |
1433 | */ | |
1434 | if (transport && | |
1435 | sack->num_gap_ack_blocks && | |
1436 | q->asoc->peer.primary_path->cacc. | |
1437 | changeover_active) | |
1438 | transport->cacc.cacc_saw_newack | |
1439 | = 1; | |
1440 | } | |
1441 | ||
1442 | list_add_tail(&tchunk->transmitted_list, | |
1443 | &q->sacked); | |
1444 | } else { | |
1445 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1446 | * M2) Each time a SACK arrives reporting | |
1447 | * 'Stray DATA chunk(s)' record the highest TSN | |
1448 | * reported as newly acknowledged, call this | |
1449 | * value 'HighestTSNinSack'. A newly | |
1450 | * acknowledged DATA chunk is one not | |
1451 | * previously acknowledged in a SACK. | |
1452 | * | |
1453 | * When the SCTP sender of data receives a SACK | |
1454 | * chunk that acknowledges, for the first time, | |
1455 | * the receipt of a DATA chunk, all the still | |
1456 | * unacknowledged DATA chunks whose TSN is | |
1457 | * older than that newly acknowledged DATA | |
1458 | * chunk, are qualified as 'Stray DATA chunks'. | |
1459 | */ | |
1da177e4 LT |
1460 | list_add_tail(lchunk, &tlist); |
1461 | } | |
1da177e4 LT |
1462 | } else { |
1463 | if (tchunk->tsn_gap_acked) { | |
bb33381d DB |
1464 | pr_debug("%s: receiver reneged on data TSN:0x%x\n", |
1465 | __func__, tsn); | |
1466 | ||
1da177e4 LT |
1467 | tchunk->tsn_gap_acked = 0; |
1468 | ||
31b02e15 VY |
1469 | if (tchunk->transport) |
1470 | bytes_acked -= sctp_data_size(tchunk); | |
1da177e4 LT |
1471 | |
1472 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1473 | * | |
1474 | * R4) Whenever a SACK is received missing a | |
1475 | * TSN that was previously acknowledged via a | |
1476 | * Gap Ack Block, start T3-rtx for the | |
1477 | * destination address to which the DATA | |
1478 | * chunk was originally | |
1479 | * transmitted if it is not already running. | |
1480 | */ | |
1481 | restart_timer = 1; | |
1482 | } | |
1483 | ||
1484 | list_add_tail(lchunk, &tlist); | |
1da177e4 LT |
1485 | } |
1486 | } | |
1487 | ||
1da177e4 LT |
1488 | if (transport) { |
1489 | if (bytes_acked) { | |
f8d96052 TG |
1490 | struct sctp_association *asoc = transport->asoc; |
1491 | ||
31b02e15 VY |
1492 | /* We may have counted DATA that was migrated |
1493 | * to this transport due to DEL-IP operation. | |
1494 | * Subtract those bytes, since the were never | |
1495 | * send on this transport and shouldn't be | |
1496 | * credited to this transport. | |
1497 | */ | |
1498 | bytes_acked -= migrate_bytes; | |
1499 | ||
1da177e4 LT |
1500 | /* 8.2. When an outstanding TSN is acknowledged, |
1501 | * the endpoint shall clear the error counter of | |
1502 | * the destination transport address to which the | |
1503 | * DATA chunk was last sent. | |
1504 | * The association's overall error counter is | |
1505 | * also cleared. | |
1506 | */ | |
1507 | transport->error_count = 0; | |
1508 | transport->asoc->overall_error_count = 0; | |
8c2f414a | 1509 | forward_progress = true; |
1da177e4 | 1510 | |
f8d96052 TG |
1511 | /* |
1512 | * While in SHUTDOWN PENDING, we may have started | |
1513 | * the T5 shutdown guard timer after reaching the | |
1514 | * retransmission limit. Stop that timer as soon | |
1515 | * as the receiver acknowledged any data. | |
1516 | */ | |
1517 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING && | |
1518 | del_timer(&asoc->timers | |
1519 | [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD])) | |
1520 | sctp_association_put(asoc); | |
1521 | ||
1da177e4 LT |
1522 | /* Mark the destination transport address as |
1523 | * active if it is not so marked. | |
1524 | */ | |
edfee033 ND |
1525 | if ((transport->state == SCTP_INACTIVE || |
1526 | transport->state == SCTP_UNCONFIRMED) && | |
1527 | sctp_cmp_addr_exact(&transport->ipaddr, saddr)) { | |
1da177e4 LT |
1528 | sctp_assoc_control_transport( |
1529 | transport->asoc, | |
1530 | transport, | |
1531 | SCTP_TRANSPORT_UP, | |
1532 | SCTP_RECEIVED_SACK); | |
1533 | } | |
1534 | ||
1535 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1536 | bytes_acked); | |
1537 | ||
1538 | transport->flight_size -= bytes_acked; | |
8b73a07c GJ |
1539 | if (transport->flight_size == 0) |
1540 | transport->partial_bytes_acked = 0; | |
31b02e15 | 1541 | q->outstanding_bytes -= bytes_acked + migrate_bytes; |
1da177e4 LT |
1542 | } else { |
1543 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1544 | * When a sender is doing zero window probing, it | |
1545 | * should not timeout the association if it continues | |
1546 | * to receive new packets from the receiver. The | |
1547 | * reason is that the receiver MAY keep its window | |
1548 | * closed for an indefinite time. | |
1549 | * A sender is doing zero window probing when the | |
1550 | * receiver's advertised window is zero, and there is | |
1551 | * only one data chunk in flight to the receiver. | |
f8d96052 TG |
1552 | * |
1553 | * Allow the association to timeout while in SHUTDOWN | |
1554 | * PENDING or SHUTDOWN RECEIVED in case the receiver | |
1555 | * stays in zero window mode forever. | |
1da177e4 LT |
1556 | */ |
1557 | if (!q->asoc->peer.rwnd && | |
1558 | !list_empty(&tlist) && | |
f8d96052 TG |
1559 | (sack_ctsn+2 == q->asoc->next_tsn) && |
1560 | q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) { | |
bb33381d DB |
1561 | pr_debug("%s: sack received for zero window " |
1562 | "probe:%u\n", __func__, sack_ctsn); | |
1563 | ||
1da177e4 LT |
1564 | q->asoc->overall_error_count = 0; |
1565 | transport->error_count = 0; | |
1566 | } | |
1567 | } | |
1568 | ||
1569 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1570 | * | |
1571 | * R2) Whenever all outstanding data sent to an address have | |
1572 | * been acknowledged, turn off the T3-rtx timer of that | |
1573 | * address. | |
1574 | */ | |
1575 | if (!transport->flight_size) { | |
25cc4ae9 | 1576 | if (del_timer(&transport->T3_rtx_timer)) |
1da177e4 | 1577 | sctp_transport_put(transport); |
1da177e4 LT |
1578 | } else if (restart_timer) { |
1579 | if (!mod_timer(&transport->T3_rtx_timer, | |
1580 | jiffies + transport->rto)) | |
1581 | sctp_transport_hold(transport); | |
1582 | } | |
8c2f414a DB |
1583 | |
1584 | if (forward_progress) { | |
1585 | if (transport->dst) | |
1586 | dst_confirm(transport->dst); | |
1587 | } | |
1da177e4 LT |
1588 | } |
1589 | ||
1590 | list_splice(&tlist, transmitted_queue); | |
1591 | } | |
1592 | ||
1593 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1594 | static void sctp_mark_missing(struct sctp_outq *q, | |
1595 | struct list_head *transmitted_queue, | |
1596 | struct sctp_transport *transport, | |
1597 | __u32 highest_new_tsn_in_sack, | |
1598 | int count_of_newacks) | |
1599 | { | |
1600 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1601 | __u32 tsn; |
1602 | char do_fast_retransmit = 0; | |
ea862c8d VY |
1603 | struct sctp_association *asoc = q->asoc; |
1604 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1da177e4 | 1605 | |
9dbc15f0 | 1606 | list_for_each_entry(chunk, transmitted_queue, transmitted_list) { |
1da177e4 | 1607 | |
1da177e4 LT |
1608 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1609 | ||
1610 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1611 | * 'Unacknowledged TSN's', if the TSN number of an | |
1612 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1613 | * value, increment the 'TSN.Missing.Report' count on that | |
1614 | * chunk if it has NOT been fast retransmitted or marked for | |
1615 | * fast retransmit already. | |
1616 | */ | |
c226ef9b | 1617 | if (chunk->fast_retransmit == SCTP_CAN_FRTX && |
1da177e4 LT |
1618 | !chunk->tsn_gap_acked && |
1619 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1620 | ||
1621 | /* SFR-CACC may require us to skip marking | |
1622 | * this chunk as missing. | |
1623 | */ | |
f246a7b7 VY |
1624 | if (!transport || !sctp_cacc_skip(primary, |
1625 | chunk->transport, | |
1626 | count_of_newacks, tsn)) { | |
1da177e4 LT |
1627 | chunk->tsn_missing_report++; |
1628 | ||
bb33381d DB |
1629 | pr_debug("%s: tsn:0x%x missing counter:%d\n", |
1630 | __func__, tsn, chunk->tsn_missing_report); | |
1da177e4 LT |
1631 | } |
1632 | } | |
1633 | /* | |
1634 | * M4) If any DATA chunk is found to have a | |
1635 | * 'TSN.Missing.Report' | |
27852c26 | 1636 | * value larger than or equal to 3, mark that chunk for |
1da177e4 LT |
1637 | * retransmission and start the fast retransmit procedure. |
1638 | */ | |
1639 | ||
27852c26 | 1640 | if (chunk->tsn_missing_report >= 3) { |
c226ef9b | 1641 | chunk->fast_retransmit = SCTP_NEED_FRTX; |
1da177e4 LT |
1642 | do_fast_retransmit = 1; |
1643 | } | |
1644 | } | |
1645 | ||
1646 | if (transport) { | |
1647 | if (do_fast_retransmit) | |
1648 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1649 | ||
bb33381d DB |
1650 | pr_debug("%s: transport:%p, cwnd:%d, ssthresh:%d, " |
1651 | "flight_size:%d, pba:%d\n", __func__, transport, | |
1652 | transport->cwnd, transport->ssthresh, | |
1653 | transport->flight_size, transport->partial_bytes_acked); | |
1da177e4 LT |
1654 | } |
1655 | } | |
1656 | ||
1657 | /* Is the given TSN acked by this packet? */ | |
1658 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1659 | { | |
1660 | int i; | |
1661 | sctp_sack_variable_t *frags; | |
1662 | __u16 gap; | |
1663 | __u32 ctsn = ntohl(sack->cum_tsn_ack); | |
1664 | ||
d808ad9a | 1665 | if (TSN_lte(tsn, ctsn)) |
1da177e4 LT |
1666 | goto pass; |
1667 | ||
1668 | /* 3.3.4 Selective Acknowledgement (SACK) (3): | |
1669 | * | |
1670 | * Gap Ack Blocks: | |
1671 | * These fields contain the Gap Ack Blocks. They are repeated | |
1672 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1673 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1674 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1675 | * Ack + Gap Ack Block Start) and less than or equal to | |
1676 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1677 | * Block are assumed to have been received correctly. | |
1678 | */ | |
1679 | ||
1680 | frags = sack->variable; | |
1681 | gap = tsn - ctsn; | |
1682 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { | |
1683 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && | |
1684 | TSN_lte(gap, ntohs(frags[i].gab.end))) | |
1685 | goto pass; | |
1686 | } | |
1687 | ||
1688 | return 0; | |
1689 | pass: | |
1690 | return 1; | |
1691 | } | |
1692 | ||
1693 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
9f81bcd9 | 1694 | int nskips, __be16 stream) |
1da177e4 LT |
1695 | { |
1696 | int i; | |
1697 | ||
1698 | for (i = 0; i < nskips; i++) { | |
1699 | if (skiplist[i].stream == stream) | |
1700 | return i; | |
1701 | } | |
1702 | return i; | |
1703 | } | |
1704 | ||
1705 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
1706 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) | |
1707 | { | |
1708 | struct sctp_association *asoc = q->asoc; | |
1709 | struct sctp_chunk *ftsn_chunk = NULL; | |
1710 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1711 | int nskips = 0; | |
1712 | int skip_pos = 0; | |
1713 | __u32 tsn; | |
1714 | struct sctp_chunk *chunk; | |
1715 | struct list_head *lchunk, *temp; | |
1716 | ||
76595024 WY |
1717 | if (!asoc->peer.prsctp_capable) |
1718 | return; | |
1719 | ||
1da177e4 LT |
1720 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
1721 | * received SACK. | |
d808ad9a | 1722 | * |
1da177e4 LT |
1723 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
1724 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1725 | */ | |
1726 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1727 | asoc->adv_peer_ack_point = ctsn; | |
1728 | ||
1729 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1730 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1731 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1732 | * shown in the following example: | |
1733 | * | |
1734 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1735 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
d808ad9a | 1736 | * |
1da177e4 LT |
1737 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
1738 | * normal SACK processing local advancement | |
1739 | * ... ... | |
1740 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1741 | * 103 abandoned 103 abandoned | |
1742 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1743 | * 105 105 | |
1744 | * 106 acked 106 acked | |
1745 | * ... ... | |
1746 | * | |
1747 | * In this example, the data sender successfully advanced the | |
1748 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1749 | */ | |
1750 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1751 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1752 | transmitted_list); | |
1753 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1754 | ||
1755 | /* Remove any chunks in the abandoned queue that are acked by | |
1756 | * the ctsn. | |
d808ad9a | 1757 | */ |
1da177e4 LT |
1758 | if (TSN_lte(tsn, ctsn)) { |
1759 | list_del_init(lchunk); | |
1da177e4 LT |
1760 | sctp_chunk_free(chunk); |
1761 | } else { | |
1762 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1763 | asoc->adv_peer_ack_point = tsn; | |
1764 | if (chunk->chunk_hdr->flags & | |
1765 | SCTP_DATA_UNORDERED) | |
1766 | continue; | |
1767 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1768 | nskips, | |
1769 | chunk->subh.data_hdr->stream); | |
1770 | ftsn_skip_arr[skip_pos].stream = | |
1771 | chunk->subh.data_hdr->stream; | |
1772 | ftsn_skip_arr[skip_pos].ssn = | |
1773 | chunk->subh.data_hdr->ssn; | |
1774 | if (skip_pos == nskips) | |
1775 | nskips++; | |
1776 | if (nskips == 10) | |
1777 | break; | |
1778 | } else | |
1779 | break; | |
1780 | } | |
1781 | } | |
1782 | ||
1783 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1784 | * is greater than the Cumulative TSN ACK carried in the received | |
1785 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1786 | * chunk containing the latest value of the | |
1787 | * "Advanced.Peer.Ack.Point". | |
1788 | * | |
1789 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1790 | * list each stream and sequence number in the forwarded TSN. This | |
1791 | * information will enable the receiver to easily find any | |
1792 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1793 | * SHOULD only be reported once; this means that if multiple | |
1794 | * abandoned messages occur in the same stream then only the | |
1795 | * highest abandoned stream sequence number is reported. If the | |
1796 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1797 | * the sender of the FORWARD TSN SHOULD lower the | |
1798 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1799 | * single MTU. | |
1800 | */ | |
1801 | if (asoc->adv_peer_ack_point > ctsn) | |
1802 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
d808ad9a | 1803 | nskips, &ftsn_skip_arr[0]); |
1da177e4 LT |
1804 | |
1805 | if (ftsn_chunk) { | |
79af02c2 | 1806 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
b01a2407 | 1807 | SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
1808 | } |
1809 | } |