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47505b8b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
60c778b2 | 2 | /* SCTP kernel implementation |
1da177e4 LT |
3 | * (C) Copyright IBM Corp. 2001, 2004 |
4 | * Copyright (c) 1999-2000 Cisco, Inc. | |
5 | * Copyright (c) 1999-2001 Motorola, Inc. | |
6 | * Copyright (c) 2001-2003 Intel Corp. | |
7 | * | |
60c778b2 | 8 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
9 | * |
10 | * These functions implement the sctp_outq class. The outqueue handles | |
11 | * bundling and queueing of outgoing SCTP chunks. | |
12 | * | |
1da177e4 LT |
13 | * Please send any bug reports or fixes you make to the |
14 | * email address(es): | |
91705c61 | 15 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 16 | * |
1da177e4 LT |
17 | * Written or modified by: |
18 | * La Monte H.P. Yarroll <piggy@acm.org> | |
19 | * Karl Knutson <karl@athena.chicago.il.us> | |
20 | * Perry Melange <pmelange@null.cc.uic.edu> | |
21 | * Xingang Guo <xingang.guo@intel.com> | |
22 | * Hui Huang <hui.huang@nokia.com> | |
23 | * Sridhar Samudrala <sri@us.ibm.com> | |
24 | * Jon Grimm <jgrimm@us.ibm.com> | |
1da177e4 LT |
25 | */ |
26 | ||
145ce502 JP |
27 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
28 | ||
1da177e4 LT |
29 | #include <linux/types.h> |
30 | #include <linux/list.h> /* For struct list_head */ | |
31 | #include <linux/socket.h> | |
32 | #include <linux/ip.h> | |
5a0e3ad6 | 33 | #include <linux/slab.h> |
1da177e4 LT |
34 | #include <net/sock.h> /* For skb_set_owner_w */ |
35 | ||
36 | #include <net/sctp/sctp.h> | |
37 | #include <net/sctp/sm.h> | |
5bbbbe32 | 38 | #include <net/sctp/stream_sched.h> |
1da177e4 LT |
39 | |
40 | /* Declare internal functions here. */ | |
41 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); | |
42 | static void sctp_check_transmitted(struct sctp_outq *q, | |
43 | struct list_head *transmitted_queue, | |
44 | struct sctp_transport *transport, | |
edfee033 | 45 | union sctp_addr *saddr, |
1da177e4 | 46 | struct sctp_sackhdr *sack, |
bfa0d984 | 47 | __u32 *highest_new_tsn); |
1da177e4 LT |
48 | |
49 | static void sctp_mark_missing(struct sctp_outq *q, | |
50 | struct list_head *transmitted_queue, | |
51 | struct sctp_transport *transport, | |
52 | __u32 highest_new_tsn, | |
53 | int count_of_newacks); | |
54 | ||
83dbc3d4 | 55 | static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp); |
abd0b198 | 56 | |
1da177e4 LT |
57 | /* Add data to the front of the queue. */ |
58 | static inline void sctp_outq_head_data(struct sctp_outq *q, | |
5bbbbe32 | 59 | struct sctp_chunk *ch) |
1da177e4 | 60 | { |
5bbbbe32 MRL |
61 | struct sctp_stream_out_ext *oute; |
62 | __u16 stream; | |
63 | ||
79af02c2 | 64 | list_add(&ch->list, &q->out_chunk_list); |
1da177e4 | 65 | q->out_qlen += ch->skb->len; |
5bbbbe32 MRL |
66 | |
67 | stream = sctp_chunk_stream_no(ch); | |
05364ca0 | 68 | oute = SCTP_SO(&q->asoc->stream, stream)->ext; |
5bbbbe32 | 69 | list_add(&ch->stream_list, &oute->outq); |
1da177e4 LT |
70 | } |
71 | ||
72 | /* Take data from the front of the queue. */ | |
73 | static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) | |
74 | { | |
5bbbbe32 | 75 | return q->sched->dequeue(q); |
1da177e4 | 76 | } |
5bbbbe32 | 77 | |
1da177e4 LT |
78 | /* Add data chunk to the end of the queue. */ |
79 | static inline void sctp_outq_tail_data(struct sctp_outq *q, | |
80 | struct sctp_chunk *ch) | |
81 | { | |
5bbbbe32 MRL |
82 | struct sctp_stream_out_ext *oute; |
83 | __u16 stream; | |
84 | ||
79af02c2 | 85 | list_add_tail(&ch->list, &q->out_chunk_list); |
1da177e4 | 86 | q->out_qlen += ch->skb->len; |
5bbbbe32 MRL |
87 | |
88 | stream = sctp_chunk_stream_no(ch); | |
05364ca0 | 89 | oute = SCTP_SO(&q->asoc->stream, stream)->ext; |
5bbbbe32 | 90 | list_add_tail(&ch->stream_list, &oute->outq); |
1da177e4 LT |
91 | } |
92 | ||
93 | /* | |
94 | * SFR-CACC algorithm: | |
95 | * D) If count_of_newacks is greater than or equal to 2 | |
96 | * and t was not sent to the current primary then the | |
97 | * sender MUST NOT increment missing report count for t. | |
98 | */ | |
99 | static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, | |
100 | struct sctp_transport *transport, | |
101 | int count_of_newacks) | |
102 | { | |
cb3f837b | 103 | if (count_of_newacks >= 2 && transport != primary) |
1da177e4 LT |
104 | return 1; |
105 | return 0; | |
106 | } | |
107 | ||
108 | /* | |
109 | * SFR-CACC algorithm: | |
110 | * F) If count_of_newacks is less than 2, let d be the | |
111 | * destination to which t was sent. If cacc_saw_newack | |
112 | * is 0 for destination d, then the sender MUST NOT | |
113 | * increment missing report count for t. | |
114 | */ | |
115 | static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, | |
116 | int count_of_newacks) | |
117 | { | |
f246a7b7 VY |
118 | if (count_of_newacks < 2 && |
119 | (transport && !transport->cacc.cacc_saw_newack)) | |
1da177e4 LT |
120 | return 1; |
121 | return 0; | |
122 | } | |
123 | ||
124 | /* | |
125 | * SFR-CACC algorithm: | |
126 | * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD | |
127 | * execute steps C, D, F. | |
128 | * | |
129 | * C has been implemented in sctp_outq_sack | |
130 | */ | |
131 | static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, | |
132 | struct sctp_transport *transport, | |
133 | int count_of_newacks) | |
134 | { | |
135 | if (!primary->cacc.cycling_changeover) { | |
136 | if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks)) | |
137 | return 1; | |
138 | if (sctp_cacc_skip_3_1_f(transport, count_of_newacks)) | |
139 | return 1; | |
140 | return 0; | |
141 | } | |
142 | return 0; | |
143 | } | |
144 | ||
145 | /* | |
146 | * SFR-CACC algorithm: | |
147 | * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less | |
148 | * than next_tsn_at_change of the current primary, then | |
149 | * the sender MUST NOT increment missing report count | |
150 | * for t. | |
151 | */ | |
152 | static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) | |
153 | { | |
154 | if (primary->cacc.cycling_changeover && | |
155 | TSN_lt(tsn, primary->cacc.next_tsn_at_change)) | |
156 | return 1; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | /* | |
161 | * SFR-CACC algorithm: | |
162 | * 3) If the missing report count for TSN t is to be | |
163 | * incremented according to [RFC2960] and | |
164 | * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, | |
25985edc | 165 | * then the sender MUST further execute steps 3.1 and |
1da177e4 LT |
166 | * 3.2 to determine if the missing report count for |
167 | * TSN t SHOULD NOT be incremented. | |
168 | * | |
169 | * 3.3) If 3.1 and 3.2 do not dictate that the missing | |
170 | * report count for t should not be incremented, then | |
25985edc | 171 | * the sender SHOULD increment missing report count for |
1da177e4 LT |
172 | * t (according to [RFC2960] and [SCTP_STEWART_2002]). |
173 | */ | |
174 | static inline int sctp_cacc_skip(struct sctp_transport *primary, | |
175 | struct sctp_transport *transport, | |
176 | int count_of_newacks, | |
177 | __u32 tsn) | |
178 | { | |
179 | if (primary->cacc.changeover_active && | |
f64f9e71 JP |
180 | (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) || |
181 | sctp_cacc_skip_3_2(primary, tsn))) | |
1da177e4 LT |
182 | return 1; |
183 | return 0; | |
184 | } | |
185 | ||
186 | /* Initialize an existing sctp_outq. This does the boring stuff. | |
187 | * You still need to define handlers if you really want to DO | |
188 | * something with this structure... | |
189 | */ | |
190 | void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) | |
191 | { | |
c5c7774d NH |
192 | memset(q, 0, sizeof(struct sctp_outq)); |
193 | ||
1da177e4 | 194 | q->asoc = asoc; |
79af02c2 DM |
195 | INIT_LIST_HEAD(&q->out_chunk_list); |
196 | INIT_LIST_HEAD(&q->control_chunk_list); | |
1da177e4 LT |
197 | INIT_LIST_HEAD(&q->retransmit); |
198 | INIT_LIST_HEAD(&q->sacked); | |
199 | INIT_LIST_HEAD(&q->abandoned); | |
7efba10d | 200 | sctp_sched_set_sched(asoc, sctp_sk(asoc->base.sk)->default_ss); |
1da177e4 LT |
201 | } |
202 | ||
203 | /* Free the outqueue structure and any related pending chunks. | |
204 | */ | |
2f94aabd | 205 | static void __sctp_outq_teardown(struct sctp_outq *q) |
1da177e4 LT |
206 | { |
207 | struct sctp_transport *transport; | |
9dbc15f0 | 208 | struct list_head *lchunk, *temp; |
79af02c2 | 209 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
210 | |
211 | /* Throw away unacknowledged chunks. */ | |
9dbc15f0 RD |
212 | list_for_each_entry(transport, &q->asoc->peer.transport_addr_list, |
213 | transports) { | |
1da177e4 LT |
214 | while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) { |
215 | chunk = list_entry(lchunk, struct sctp_chunk, | |
216 | transmitted_list); | |
217 | /* Mark as part of a failed message. */ | |
218 | sctp_chunk_fail(chunk, q->error); | |
219 | sctp_chunk_free(chunk); | |
220 | } | |
221 | } | |
222 | ||
223 | /* Throw away chunks that have been gap ACKed. */ | |
224 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
225 | list_del_init(lchunk); | |
226 | chunk = list_entry(lchunk, struct sctp_chunk, | |
227 | transmitted_list); | |
228 | sctp_chunk_fail(chunk, q->error); | |
229 | sctp_chunk_free(chunk); | |
230 | } | |
231 | ||
232 | /* Throw away any chunks in the retransmit queue. */ | |
233 | list_for_each_safe(lchunk, temp, &q->retransmit) { | |
234 | list_del_init(lchunk); | |
235 | chunk = list_entry(lchunk, struct sctp_chunk, | |
236 | transmitted_list); | |
237 | sctp_chunk_fail(chunk, q->error); | |
238 | sctp_chunk_free(chunk); | |
239 | } | |
240 | ||
241 | /* Throw away any chunks that are in the abandoned queue. */ | |
242 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
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 leftover data chunks. */ | |
251 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { | |
5bbbbe32 | 252 | sctp_sched_dequeue_done(q, chunk); |
1da177e4 LT |
253 | |
254 | /* Mark as send failure. */ | |
255 | sctp_chunk_fail(chunk, q->error); | |
256 | sctp_chunk_free(chunk); | |
257 | } | |
258 | ||
1da177e4 | 259 | /* Throw away any leftover control chunks. */ |
79af02c2 DM |
260 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
261 | list_del_init(&chunk->list); | |
1da177e4 | 262 | sctp_chunk_free(chunk); |
79af02c2 | 263 | } |
1da177e4 LT |
264 | } |
265 | ||
2f94aabd NH |
266 | void sctp_outq_teardown(struct sctp_outq *q) |
267 | { | |
268 | __sctp_outq_teardown(q); | |
269 | sctp_outq_init(q->asoc, q); | |
270 | } | |
271 | ||
1da177e4 LT |
272 | /* Free the outqueue structure and any related pending chunks. */ |
273 | void sctp_outq_free(struct sctp_outq *q) | |
274 | { | |
275 | /* Throw away leftover chunks. */ | |
2f94aabd | 276 | __sctp_outq_teardown(q); |
1da177e4 LT |
277 | } |
278 | ||
279 | /* Put a new chunk in an sctp_outq. */ | |
83dbc3d4 | 280 | void sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk, gfp_t gfp) |
1da177e4 | 281 | { |
b01a2407 | 282 | struct net *net = sock_net(q->asoc->base.sk); |
1da177e4 | 283 | |
bb33381d DB |
284 | pr_debug("%s: outq:%p, chunk:%p[%s]\n", __func__, q, chunk, |
285 | chunk && chunk->chunk_hdr ? | |
286 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
287 | "illegal chunk"); | |
1da177e4 LT |
288 | |
289 | /* If it is data, queue it up, otherwise, send it | |
290 | * immediately. | |
291 | */ | |
ec7b9519 | 292 | if (sctp_chunk_is_data(chunk)) { |
2c89791e XL |
293 | pr_debug("%s: outqueueing: outq:%p, chunk:%p[%s])\n", |
294 | __func__, q, chunk, chunk && chunk->chunk_hdr ? | |
295 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : | |
296 | "illegal chunk"); | |
297 | ||
2c89791e | 298 | sctp_outq_tail_data(q, chunk); |
b50afd20 | 299 | if (chunk->asoc->peer.prsctp_capable && |
2c89791e XL |
300 | SCTP_PR_PRIO_ENABLED(chunk->sinfo.sinfo_flags)) |
301 | chunk->asoc->sent_cnt_removable++; | |
302 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
303 | SCTP_INC_STATS(net, SCTP_MIB_OUTUNORDERCHUNKS); | |
304 | else | |
305 | SCTP_INC_STATS(net, SCTP_MIB_OUTORDERCHUNKS); | |
1da177e4 | 306 | } else { |
79af02c2 | 307 | list_add_tail(&chunk->list, &q->control_chunk_list); |
b01a2407 | 308 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
309 | } |
310 | ||
1da177e4 | 311 | if (!q->cork) |
83dbc3d4 | 312 | sctp_outq_flush(q, 0, gfp); |
1da177e4 LT |
313 | } |
314 | ||
315 | /* Insert a chunk into the sorted list based on the TSNs. The retransmit list | |
316 | * and the abandoned list are in ascending order. | |
317 | */ | |
318 | static void sctp_insert_list(struct list_head *head, struct list_head *new) | |
319 | { | |
320 | struct list_head *pos; | |
321 | struct sctp_chunk *nchunk, *lchunk; | |
322 | __u32 ntsn, ltsn; | |
323 | int done = 0; | |
324 | ||
325 | nchunk = list_entry(new, struct sctp_chunk, transmitted_list); | |
326 | ntsn = ntohl(nchunk->subh.data_hdr->tsn); | |
327 | ||
328 | list_for_each(pos, head) { | |
329 | lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); | |
330 | ltsn = ntohl(lchunk->subh.data_hdr->tsn); | |
331 | if (TSN_lt(ntsn, ltsn)) { | |
332 | list_add(new, pos->prev); | |
333 | done = 1; | |
334 | break; | |
335 | } | |
336 | } | |
337 | if (!done) | |
d808ad9a | 338 | list_add_tail(new, head); |
1da177e4 LT |
339 | } |
340 | ||
8dbdf1f5 XL |
341 | static int sctp_prsctp_prune_sent(struct sctp_association *asoc, |
342 | struct sctp_sndrcvinfo *sinfo, | |
343 | struct list_head *queue, int msg_len) | |
344 | { | |
345 | struct sctp_chunk *chk, *temp; | |
346 | ||
347 | list_for_each_entry_safe(chk, temp, queue, transmitted_list) { | |
d229d48d XL |
348 | struct sctp_stream_out *streamout; |
349 | ||
e5f61296 XL |
350 | if (!chk->msg->abandoned && |
351 | (!SCTP_PR_PRIO_ENABLED(chk->sinfo.sinfo_flags) || | |
352 | chk->sinfo.sinfo_timetolive <= sinfo->sinfo_timetolive)) | |
8dbdf1f5 XL |
353 | continue; |
354 | ||
e5f61296 | 355 | chk->msg->abandoned = 1; |
8dbdf1f5 XL |
356 | list_del_init(&chk->transmitted_list); |
357 | sctp_insert_list(&asoc->outqueue.abandoned, | |
358 | &chk->transmitted_list); | |
359 | ||
05364ca0 | 360 | streamout = SCTP_SO(&asoc->stream, chk->sinfo.sinfo_stream); |
8dbdf1f5 XL |
361 | asoc->sent_cnt_removable--; |
362 | asoc->abandoned_sent[SCTP_PR_INDEX(PRIO)]++; | |
f952be79 | 363 | streamout->ext->abandoned_sent[SCTP_PR_INDEX(PRIO)]++; |
8dbdf1f5 | 364 | |
d30fc512 XL |
365 | if (queue != &asoc->outqueue.retransmit && |
366 | !chk->tsn_gap_acked) { | |
8dbdf1f5 XL |
367 | if (chk->transport) |
368 | chk->transport->flight_size -= | |
369 | sctp_data_size(chk); | |
370 | asoc->outqueue.outstanding_bytes -= sctp_data_size(chk); | |
371 | } | |
372 | ||
605c0ac1 | 373 | msg_len -= chk->skb->truesize + sizeof(struct sctp_chunk); |
8dbdf1f5 XL |
374 | if (msg_len <= 0) |
375 | break; | |
376 | } | |
377 | ||
378 | return msg_len; | |
379 | } | |
380 | ||
381 | static int sctp_prsctp_prune_unsent(struct sctp_association *asoc, | |
23bb09cf | 382 | struct sctp_sndrcvinfo *sinfo, int msg_len) |
8dbdf1f5 | 383 | { |
23bb09cf | 384 | struct sctp_outq *q = &asoc->outqueue; |
8dbdf1f5 XL |
385 | struct sctp_chunk *chk, *temp; |
386 | ||
5bbbbe32 MRL |
387 | q->sched->unsched_all(&asoc->stream); |
388 | ||
23bb09cf | 389 | list_for_each_entry_safe(chk, temp, &q->out_chunk_list, list) { |
e5f61296 | 390 | if (!chk->msg->abandoned && |
779edd73 XL |
391 | (!(chk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG) || |
392 | !SCTP_PR_PRIO_ENABLED(chk->sinfo.sinfo_flags) || | |
e5f61296 | 393 | chk->sinfo.sinfo_timetolive <= sinfo->sinfo_timetolive)) |
8dbdf1f5 XL |
394 | continue; |
395 | ||
e5f61296 | 396 | chk->msg->abandoned = 1; |
5bbbbe32 | 397 | sctp_sched_dequeue_common(q, chk); |
8dbdf1f5 XL |
398 | asoc->sent_cnt_removable--; |
399 | asoc->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++; | |
cee360ab | 400 | if (chk->sinfo.sinfo_stream < asoc->stream.outcnt) { |
d229d48d | 401 | struct sctp_stream_out *streamout = |
05364ca0 | 402 | SCTP_SO(&asoc->stream, chk->sinfo.sinfo_stream); |
d229d48d | 403 | |
f952be79 | 404 | streamout->ext->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++; |
d229d48d | 405 | } |
8dbdf1f5 | 406 | |
605c0ac1 | 407 | msg_len -= chk->skb->truesize + sizeof(struct sctp_chunk); |
8dbdf1f5 XL |
408 | sctp_chunk_free(chk); |
409 | if (msg_len <= 0) | |
410 | break; | |
411 | } | |
412 | ||
5bbbbe32 MRL |
413 | q->sched->sched_all(&asoc->stream); |
414 | ||
8dbdf1f5 XL |
415 | return msg_len; |
416 | } | |
417 | ||
418 | /* Abandon the chunks according their priorities */ | |
419 | void sctp_prsctp_prune(struct sctp_association *asoc, | |
420 | struct sctp_sndrcvinfo *sinfo, int msg_len) | |
421 | { | |
422 | struct sctp_transport *transport; | |
423 | ||
be4947bf | 424 | if (!asoc->peer.prsctp_capable || !asoc->sent_cnt_removable) |
8dbdf1f5 XL |
425 | return; |
426 | ||
427 | msg_len = sctp_prsctp_prune_sent(asoc, sinfo, | |
428 | &asoc->outqueue.retransmit, | |
429 | msg_len); | |
430 | if (msg_len <= 0) | |
431 | return; | |
432 | ||
433 | list_for_each_entry(transport, &asoc->peer.transport_addr_list, | |
434 | transports) { | |
435 | msg_len = sctp_prsctp_prune_sent(asoc, sinfo, | |
436 | &transport->transmitted, | |
437 | msg_len); | |
438 | if (msg_len <= 0) | |
439 | return; | |
440 | } | |
441 | ||
23bb09cf | 442 | sctp_prsctp_prune_unsent(asoc, sinfo, msg_len); |
8dbdf1f5 XL |
443 | } |
444 | ||
1da177e4 LT |
445 | /* Mark all the eligible packets on a transport for retransmission. */ |
446 | void sctp_retransmit_mark(struct sctp_outq *q, | |
447 | struct sctp_transport *transport, | |
b6157d8e | 448 | __u8 reason) |
1da177e4 LT |
449 | { |
450 | struct list_head *lchunk, *ltemp; | |
451 | struct sctp_chunk *chunk; | |
452 | ||
453 | /* Walk through the specified transmitted queue. */ | |
454 | list_for_each_safe(lchunk, ltemp, &transport->transmitted) { | |
455 | chunk = list_entry(lchunk, struct sctp_chunk, | |
456 | transmitted_list); | |
457 | ||
458 | /* If the chunk is abandoned, move it to abandoned list. */ | |
459 | if (sctp_chunk_abandoned(chunk)) { | |
460 | list_del_init(lchunk); | |
461 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
462 | |
463 | /* If this chunk has not been previousely acked, | |
464 | * stop considering it 'outstanding'. Our peer | |
465 | * will most likely never see it since it will | |
466 | * not be retransmitted | |
467 | */ | |
468 | if (!chunk->tsn_gap_acked) { | |
31b02e15 VY |
469 | if (chunk->transport) |
470 | chunk->transport->flight_size -= | |
471 | sctp_data_size(chunk); | |
8c4a2d41 | 472 | q->outstanding_bytes -= sctp_data_size(chunk); |
a76c0adf | 473 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
8c4a2d41 | 474 | } |
1da177e4 LT |
475 | continue; |
476 | } | |
477 | ||
b6157d8e VY |
478 | /* If we are doing retransmission due to a timeout or pmtu |
479 | * discovery, only the chunks that are not yet acked should | |
480 | * be added to the retransmit queue. | |
1da177e4 | 481 | */ |
b6157d8e | 482 | if ((reason == SCTP_RTXR_FAST_RTX && |
c226ef9b | 483 | (chunk->fast_retransmit == SCTP_NEED_FRTX)) || |
b6157d8e | 484 | (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) { |
1da177e4 LT |
485 | /* RFC 2960 6.2.1 Processing a Received SACK |
486 | * | |
487 | * C) Any time a DATA chunk is marked for | |
488 | * retransmission (via either T3-rtx timer expiration | |
489 | * (Section 6.3.3) or via fast retransmit | |
490 | * (Section 7.2.4)), add the data size of those | |
491 | * chunks to the rwnd. | |
492 | */ | |
a76c0adf | 493 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
1da177e4 | 494 | q->outstanding_bytes -= sctp_data_size(chunk); |
31b02e15 VY |
495 | if (chunk->transport) |
496 | transport->flight_size -= sctp_data_size(chunk); | |
1da177e4 LT |
497 | |
498 | /* sctpimpguide-05 Section 2.8.2 | |
499 | * M5) If a T3-rtx timer expires, the | |
500 | * 'TSN.Missing.Report' of all affected TSNs is set | |
501 | * to 0. | |
502 | */ | |
503 | chunk->tsn_missing_report = 0; | |
504 | ||
505 | /* If a chunk that is being used for RTT measurement | |
506 | * has to be retransmitted, we cannot use this chunk | |
507 | * anymore for RTT measurements. Reset rto_pending so | |
508 | * that a new RTT measurement is started when a new | |
509 | * data chunk is sent. | |
510 | */ | |
511 | if (chunk->rtt_in_progress) { | |
512 | chunk->rtt_in_progress = 0; | |
513 | transport->rto_pending = 0; | |
514 | } | |
515 | ||
516 | /* Move the chunk to the retransmit queue. The chunks | |
517 | * on the retransmit queue are always kept in order. | |
518 | */ | |
519 | list_del_init(lchunk); | |
520 | sctp_insert_list(&q->retransmit, lchunk); | |
521 | } | |
522 | } | |
523 | ||
bb33381d DB |
524 | pr_debug("%s: transport:%p, reason:%d, cwnd:%d, ssthresh:%d, " |
525 | "flight_size:%d, pba:%d\n", __func__, transport, reason, | |
526 | transport->cwnd, transport->ssthresh, transport->flight_size, | |
527 | transport->partial_bytes_acked); | |
1da177e4 LT |
528 | } |
529 | ||
530 | /* Mark all the eligible packets on a transport for retransmission and force | |
531 | * one packet out. | |
532 | */ | |
533 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, | |
125c2982 | 534 | enum sctp_retransmit_reason reason) |
1da177e4 | 535 | { |
b01a2407 | 536 | struct net *net = sock_net(q->asoc->base.sk); |
1da177e4 | 537 | |
cb3f837b | 538 | switch (reason) { |
1da177e4 | 539 | case SCTP_RTXR_T3_RTX: |
b01a2407 | 540 | SCTP_INC_STATS(net, SCTP_MIB_T3_RETRANSMITS); |
1da177e4 LT |
541 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); |
542 | /* Update the retran path if the T3-rtx timer has expired for | |
543 | * the current retran path. | |
544 | */ | |
545 | if (transport == transport->asoc->peer.retran_path) | |
546 | sctp_assoc_update_retran_path(transport->asoc); | |
58fbbed4 NH |
547 | transport->asoc->rtx_data_chunks += |
548 | transport->asoc->unack_data; | |
1da177e4 LT |
549 | break; |
550 | case SCTP_RTXR_FAST_RTX: | |
b01a2407 | 551 | SCTP_INC_STATS(net, SCTP_MIB_FAST_RETRANSMITS); |
1da177e4 | 552 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); |
62aeaff5 | 553 | q->fast_rtx = 1; |
1da177e4 LT |
554 | break; |
555 | case SCTP_RTXR_PMTUD: | |
b01a2407 | 556 | SCTP_INC_STATS(net, SCTP_MIB_PMTUD_RETRANSMITS); |
1da177e4 | 557 | break; |
b6157d8e | 558 | case SCTP_RTXR_T1_RTX: |
b01a2407 | 559 | SCTP_INC_STATS(net, SCTP_MIB_T1_RETRANSMITS); |
58fbbed4 | 560 | transport->asoc->init_retries++; |
b6157d8e | 561 | break; |
ac0b0462 SS |
562 | default: |
563 | BUG(); | |
1da177e4 LT |
564 | } |
565 | ||
b6157d8e | 566 | sctp_retransmit_mark(q, transport, reason); |
1da177e4 LT |
567 | |
568 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, | |
569 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by | |
570 | * following the procedures outlined in C1 - C5. | |
571 | */ | |
8b750ce5 | 572 | if (reason == SCTP_RTXR_T3_RTX) |
8e0c3b73 | 573 | q->asoc->stream.si->generate_ftsn(q, q->asoc->ctsn_ack_point); |
1da177e4 | 574 | |
8b750ce5 VY |
575 | /* Flush the queues only on timeout, since fast_rtx is only |
576 | * triggered during sack processing and the queue | |
577 | * will be flushed at the end. | |
578 | */ | |
579 | if (reason != SCTP_RTXR_FAST_RTX) | |
64519440 | 580 | sctp_outq_flush(q, /* rtx_timeout */ 1, GFP_ATOMIC); |
1da177e4 LT |
581 | } |
582 | ||
583 | /* | |
584 | * Transmit DATA chunks on the retransmit queue. Upon return from | |
96e0418e | 585 | * __sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which |
1da177e4 LT |
586 | * need to be transmitted by the caller. |
587 | * We assume that pkt->transport has already been set. | |
588 | * | |
589 | * The return value is a normal kernel error return value. | |
590 | */ | |
96e0418e | 591 | static int __sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, |
6605f694 | 592 | int rtx_timeout, int *start_timer, gfp_t gfp) |
1da177e4 | 593 | { |
1da177e4 | 594 | struct sctp_transport *transport = pkt->transport; |
1da177e4 | 595 | struct sctp_chunk *chunk, *chunk1; |
86b36f2a XL |
596 | struct list_head *lqueue; |
597 | enum sctp_xmit status; | |
1da177e4 | 598 | int error = 0; |
62aeaff5 | 599 | int timer = 0; |
8b750ce5 | 600 | int done = 0; |
86b36f2a | 601 | int fast_rtx; |
1da177e4 | 602 | |
1da177e4 | 603 | lqueue = &q->retransmit; |
62aeaff5 | 604 | fast_rtx = q->fast_rtx; |
1da177e4 | 605 | |
8b750ce5 VY |
606 | /* This loop handles time-out retransmissions, fast retransmissions, |
607 | * and retransmissions due to opening of whindow. | |
608 | * | |
609 | * RFC 2960 6.3.3 Handle T3-rtx Expiration | |
1da177e4 LT |
610 | * |
611 | * E3) Determine how many of the earliest (i.e., lowest TSN) | |
612 | * outstanding DATA chunks for the address for which the | |
613 | * T3-rtx has expired will fit into a single packet, subject | |
614 | * to the MTU constraint for the path corresponding to the | |
615 | * destination transport address to which the retransmission | |
616 | * is being sent (this may be different from the address for | |
617 | * which the timer expires [see Section 6.4]). Call this value | |
618 | * K. Bundle and retransmit those K DATA chunks in a single | |
619 | * packet to the destination endpoint. | |
620 | * | |
621 | * [Just to be painfully clear, if we are retransmitting | |
622 | * because a timeout just happened, we should send only ONE | |
623 | * packet of retransmitted data.] | |
8b750ce5 VY |
624 | * |
625 | * For fast retransmissions we also send only ONE packet. However, | |
626 | * if we are just flushing the queue due to open window, we'll | |
627 | * try to send as much as possible. | |
1da177e4 | 628 | */ |
8b750ce5 | 629 | list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { |
4c6a6f42 WY |
630 | /* If the chunk is abandoned, move it to abandoned list. */ |
631 | if (sctp_chunk_abandoned(chunk)) { | |
632 | list_del_init(&chunk->transmitted_list); | |
633 | sctp_insert_list(&q->abandoned, | |
634 | &chunk->transmitted_list); | |
635 | continue; | |
636 | } | |
1da177e4 LT |
637 | |
638 | /* Make sure that Gap Acked TSNs are not retransmitted. A | |
639 | * simple approach is just to move such TSNs out of the | |
640 | * way and into a 'transmitted' queue and skip to the | |
641 | * next chunk. | |
642 | */ | |
643 | if (chunk->tsn_gap_acked) { | |
54a27924 WY |
644 | list_move_tail(&chunk->transmitted_list, |
645 | &transport->transmitted); | |
1da177e4 LT |
646 | continue; |
647 | } | |
648 | ||
8b750ce5 VY |
649 | /* If we are doing fast retransmit, ignore non-fast_rtransmit |
650 | * chunks | |
651 | */ | |
652 | if (fast_rtx && !chunk->fast_retransmit) | |
653 | continue; | |
654 | ||
bc4f841a | 655 | redo: |
1da177e4 LT |
656 | /* Attempt to append this chunk to the packet. */ |
657 | status = sctp_packet_append_chunk(pkt, chunk); | |
658 | ||
659 | switch (status) { | |
660 | case SCTP_XMIT_PMTU_FULL: | |
bc4f841a WY |
661 | if (!pkt->has_data && !pkt->has_cookie_echo) { |
662 | /* If this packet did not contain DATA then | |
663 | * retransmission did not happen, so do it | |
664 | * again. We'll ignore the error here since | |
665 | * control chunks are already freed so there | |
666 | * is nothing we can do. | |
667 | */ | |
6605f694 | 668 | sctp_packet_transmit(pkt, gfp); |
bc4f841a WY |
669 | goto redo; |
670 | } | |
671 | ||
1da177e4 | 672 | /* Send this packet. */ |
6605f694 | 673 | error = sctp_packet_transmit(pkt, gfp); |
1da177e4 LT |
674 | |
675 | /* If we are retransmitting, we should only | |
676 | * send a single packet. | |
f246a7b7 | 677 | * Otherwise, try appending this chunk again. |
1da177e4 | 678 | */ |
8b750ce5 VY |
679 | if (rtx_timeout || fast_rtx) |
680 | done = 1; | |
f246a7b7 VY |
681 | else |
682 | goto redo; | |
1da177e4 | 683 | |
8b750ce5 | 684 | /* Bundle next chunk in the next round. */ |
1da177e4 LT |
685 | break; |
686 | ||
687 | case SCTP_XMIT_RWND_FULL: | |
d808ad9a | 688 | /* Send this packet. */ |
6605f694 | 689 | error = sctp_packet_transmit(pkt, gfp); |
1da177e4 LT |
690 | |
691 | /* Stop sending DATA as there is no more room | |
692 | * at the receiver. | |
693 | */ | |
8b750ce5 | 694 | done = 1; |
1da177e4 LT |
695 | break; |
696 | ||
526cbef7 | 697 | case SCTP_XMIT_DELAY: |
d808ad9a | 698 | /* Send this packet. */ |
6605f694 | 699 | error = sctp_packet_transmit(pkt, gfp); |
1da177e4 LT |
700 | |
701 | /* Stop sending DATA because of nagle delay. */ | |
8b750ce5 | 702 | done = 1; |
1da177e4 LT |
703 | break; |
704 | ||
705 | default: | |
706 | /* The append was successful, so add this chunk to | |
707 | * the transmitted list. | |
708 | */ | |
54a27924 WY |
709 | list_move_tail(&chunk->transmitted_list, |
710 | &transport->transmitted); | |
1da177e4 | 711 | |
d808ad9a | 712 | /* Mark the chunk as ineligible for fast retransmit |
1da177e4 LT |
713 | * after it is retransmitted. |
714 | */ | |
c226ef9b NH |
715 | if (chunk->fast_retransmit == SCTP_NEED_FRTX) |
716 | chunk->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 | 717 | |
196d6759 | 718 | q->asoc->stats.rtxchunks++; |
1da177e4 | 719 | break; |
3ff50b79 | 720 | } |
1da177e4 | 721 | |
62aeaff5 VY |
722 | /* Set the timer if there were no errors */ |
723 | if (!error && !timer) | |
724 | timer = 1; | |
725 | ||
8b750ce5 VY |
726 | if (done) |
727 | break; | |
728 | } | |
729 | ||
730 | /* If we are here due to a retransmit timeout or a fast | |
731 | * retransmit and if there are any chunks left in the retransmit | |
732 | * queue that could not fit in the PMTU sized packet, they need | |
733 | * to be marked as ineligible for a subsequent fast retransmit. | |
734 | */ | |
735 | if (rtx_timeout || fast_rtx) { | |
736 | list_for_each_entry(chunk1, lqueue, transmitted_list) { | |
c226ef9b NH |
737 | if (chunk1->fast_retransmit == SCTP_NEED_FRTX) |
738 | chunk1->fast_retransmit = SCTP_DONT_FRTX; | |
1da177e4 LT |
739 | } |
740 | } | |
741 | ||
62aeaff5 VY |
742 | *start_timer = timer; |
743 | ||
744 | /* Clear fast retransmit hint */ | |
745 | if (fast_rtx) | |
746 | q->fast_rtx = 0; | |
747 | ||
1da177e4 LT |
748 | return error; |
749 | } | |
750 | ||
751 | /* Cork the outqueue so queued chunks are really queued. */ | |
83dbc3d4 | 752 | void sctp_outq_uncork(struct sctp_outq *q, gfp_t gfp) |
1da177e4 | 753 | { |
7d54dc68 | 754 | if (q->cork) |
1da177e4 | 755 | q->cork = 0; |
dacda32e | 756 | |
83dbc3d4 | 757 | sctp_outq_flush(q, 0, gfp); |
1da177e4 LT |
758 | } |
759 | ||
b9fd6839 MRL |
760 | static int sctp_packet_singleton(struct sctp_transport *transport, |
761 | struct sctp_chunk *chunk, gfp_t gfp) | |
762 | { | |
763 | const struct sctp_association *asoc = transport->asoc; | |
764 | const __u16 sport = asoc->base.bind_addr.port; | |
765 | const __u16 dport = asoc->peer.port; | |
766 | const __u32 vtag = asoc->peer.i.init_tag; | |
767 | struct sctp_packet singleton; | |
768 | ||
769 | sctp_packet_init(&singleton, transport, sport, dport); | |
770 | sctp_packet_config(&singleton, vtag, 0); | |
771 | sctp_packet_append_chunk(&singleton, chunk); | |
772 | return sctp_packet_transmit(&singleton, gfp); | |
773 | } | |
2e3216cd | 774 | |
bb543847 MRL |
775 | /* Struct to hold the context during sctp outq flush */ |
776 | struct sctp_flush_ctx { | |
777 | struct sctp_outq *q; | |
778 | /* Current transport being used. It's NOT the same as curr active one */ | |
779 | struct sctp_transport *transport; | |
780 | /* These transports have chunks to send. */ | |
781 | struct list_head transport_list; | |
e136e965 MRL |
782 | struct sctp_association *asoc; |
783 | /* Packet on the current transport above */ | |
784 | struct sctp_packet *packet; | |
bb543847 MRL |
785 | gfp_t gfp; |
786 | }; | |
787 | ||
788 | /* transport: current transport */ | |
e136e965 | 789 | static void sctp_outq_select_transport(struct sctp_flush_ctx *ctx, |
bb543847 | 790 | struct sctp_chunk *chunk) |
0d634b0c MRL |
791 | { |
792 | struct sctp_transport *new_transport = chunk->transport; | |
0d634b0c MRL |
793 | |
794 | if (!new_transport) { | |
795 | if (!sctp_chunk_is_data(chunk)) { | |
5884f35f | 796 | /* If we have a prior transport pointer, see if |
0d634b0c MRL |
797 | * the destination address of the chunk |
798 | * matches the destination address of the | |
799 | * current transport. If not a match, then | |
800 | * try to look up the transport with a given | |
801 | * destination address. We do this because | |
802 | * after processing ASCONFs, we may have new | |
803 | * transports created. | |
804 | */ | |
bb543847 MRL |
805 | if (ctx->transport && sctp_cmp_addr_exact(&chunk->dest, |
806 | &ctx->transport->ipaddr)) | |
807 | new_transport = ctx->transport; | |
0d634b0c | 808 | else |
e136e965 | 809 | new_transport = sctp_assoc_lookup_paddr(ctx->asoc, |
0d634b0c MRL |
810 | &chunk->dest); |
811 | } | |
812 | ||
813 | /* if we still don't have a new transport, then | |
814 | * use the current active path. | |
815 | */ | |
816 | if (!new_transport) | |
e136e965 | 817 | new_transport = ctx->asoc->peer.active_path; |
0d634b0c MRL |
818 | } else { |
819 | __u8 type; | |
820 | ||
821 | switch (new_transport->state) { | |
822 | case SCTP_INACTIVE: | |
823 | case SCTP_UNCONFIRMED: | |
824 | case SCTP_PF: | |
825 | /* If the chunk is Heartbeat or Heartbeat Ack, | |
826 | * send it to chunk->transport, even if it's | |
827 | * inactive. | |
828 | * | |
829 | * 3.3.6 Heartbeat Acknowledgement: | |
830 | * ... | |
831 | * A HEARTBEAT ACK is always sent to the source IP | |
832 | * address of the IP datagram containing the | |
833 | * HEARTBEAT chunk to which this ack is responding. | |
834 | * ... | |
835 | * | |
836 | * ASCONF_ACKs also must be sent to the source. | |
837 | */ | |
838 | type = chunk->chunk_hdr->type; | |
839 | if (type != SCTP_CID_HEARTBEAT && | |
840 | type != SCTP_CID_HEARTBEAT_ACK && | |
841 | type != SCTP_CID_ASCONF_ACK) | |
e136e965 | 842 | new_transport = ctx->asoc->peer.active_path; |
0d634b0c MRL |
843 | break; |
844 | default: | |
845 | break; | |
846 | } | |
847 | } | |
848 | ||
849 | /* Are we switching transports? Take care of transport locks. */ | |
bb543847 | 850 | if (new_transport != ctx->transport) { |
bb543847 | 851 | ctx->transport = new_transport; |
e136e965 MRL |
852 | ctx->packet = &ctx->transport->packet; |
853 | ||
bb543847 MRL |
854 | if (list_empty(&ctx->transport->send_ready)) |
855 | list_add_tail(&ctx->transport->send_ready, | |
856 | &ctx->transport_list); | |
0d634b0c | 857 | |
e136e965 MRL |
858 | sctp_packet_config(ctx->packet, |
859 | ctx->asoc->peer.i.init_tag, | |
860 | ctx->asoc->peer.ecn_capable); | |
0d634b0c MRL |
861 | /* We've switched transports, so apply the |
862 | * Burst limit to the new transport. | |
863 | */ | |
bb543847 | 864 | sctp_transport_burst_limited(ctx->transport); |
0d634b0c | 865 | } |
0d634b0c MRL |
866 | } |
867 | ||
bb543847 | 868 | static void sctp_outq_flush_ctrl(struct sctp_flush_ctx *ctx) |
1da177e4 | 869 | { |
79af02c2 | 870 | struct sctp_chunk *chunk, *tmp; |
86b36f2a | 871 | enum sctp_xmit status; |
7a0b9df6 | 872 | int one_packet, error; |
1da177e4 | 873 | |
bb543847 | 874 | list_for_each_entry_safe(chunk, tmp, &ctx->q->control_chunk_list, list) { |
7a0b9df6 MRL |
875 | one_packet = 0; |
876 | ||
8a07eb0a MH |
877 | /* RFC 5061, 5.3 |
878 | * F1) This means that until such time as the ASCONF | |
879 | * containing the add is acknowledged, the sender MUST | |
880 | * NOT use the new IP address as a source for ANY SCTP | |
881 | * packet except on carrying an ASCONF Chunk. | |
882 | */ | |
e136e965 | 883 | if (ctx->asoc->src_out_of_asoc_ok && |
8a07eb0a MH |
884 | chunk->chunk_hdr->type != SCTP_CID_ASCONF) |
885 | continue; | |
886 | ||
79af02c2 DM |
887 | list_del_init(&chunk->list); |
888 | ||
0d634b0c MRL |
889 | /* Pick the right transport to use. Should always be true for |
890 | * the first chunk as we don't have a transport by then. | |
1da177e4 | 891 | */ |
e136e965 | 892 | sctp_outq_select_transport(ctx, chunk); |
1da177e4 LT |
893 | |
894 | switch (chunk->chunk_hdr->type) { | |
5884f35f | 895 | /* 6.10 Bundling |
1da177e4 LT |
896 | * ... |
897 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN | |
898 | * COMPLETE with any other chunks. [Send them immediately.] | |
899 | */ | |
900 | case SCTP_CID_INIT: | |
901 | case SCTP_CID_INIT_ACK: | |
902 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
bb543847 MRL |
903 | error = sctp_packet_singleton(ctx->transport, chunk, |
904 | ctx->gfp); | |
64519440 | 905 | if (error < 0) { |
e136e965 | 906 | ctx->asoc->base.sk->sk_err = -error; |
83dbc3d4 | 907 | return; |
64519440 | 908 | } |
1da177e4 LT |
909 | break; |
910 | ||
911 | case SCTP_CID_ABORT: | |
37f47bc9 | 912 | if (sctp_test_T_bit(chunk)) |
e136e965 | 913 | ctx->packet->vtag = ctx->asoc->c.my_vtag; |
37f47bc9 | 914 | /* fallthru */ |
7a0b9df6 | 915 | |
2e3216cd VY |
916 | /* The following chunks are "response" chunks, i.e. |
917 | * they are generated in response to something we | |
918 | * received. If we are sending these, then we can | |
919 | * send only 1 packet containing these chunks. | |
920 | */ | |
1da177e4 | 921 | case SCTP_CID_HEARTBEAT_ACK: |
1da177e4 | 922 | case SCTP_CID_SHUTDOWN_ACK: |
1da177e4 | 923 | case SCTP_CID_COOKIE_ACK: |
2e3216cd VY |
924 | case SCTP_CID_COOKIE_ECHO: |
925 | case SCTP_CID_ERROR: | |
1da177e4 | 926 | case SCTP_CID_ECN_CWR: |
1da177e4 | 927 | case SCTP_CID_ASCONF_ACK: |
2e3216cd | 928 | one_packet = 1; |
25985edc | 929 | /* Fall through */ |
2e3216cd VY |
930 | |
931 | case SCTP_CID_SACK: | |
932 | case SCTP_CID_HEARTBEAT: | |
933 | case SCTP_CID_SHUTDOWN: | |
934 | case SCTP_CID_ECN_ECNE: | |
935 | case SCTP_CID_ASCONF: | |
1da177e4 | 936 | case SCTP_CID_FWD_TSN: |
8e0c3b73 | 937 | case SCTP_CID_I_FWD_TSN: |
7f9d68ac | 938 | case SCTP_CID_RECONF: |
e136e965 | 939 | status = sctp_packet_transmit_chunk(ctx->packet, chunk, |
bb543847 | 940 | one_packet, ctx->gfp); |
7a0b9df6 | 941 | if (status != SCTP_XMIT_OK) { |
2e3216cd | 942 | /* put the chunk back */ |
bb543847 | 943 | list_add(&chunk->list, &ctx->q->control_chunk_list); |
7f9d68ac XL |
944 | break; |
945 | } | |
946 | ||
e136e965 | 947 | ctx->asoc->stats.octrlchunks++; |
7f9d68ac XL |
948 | /* PR-SCTP C5) If a FORWARD TSN is sent, the |
949 | * sender MUST assure that at least one T3-rtx | |
950 | * timer is running. | |
951 | */ | |
8e0c3b73 XL |
952 | if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN || |
953 | chunk->chunk_hdr->type == SCTP_CID_I_FWD_TSN) { | |
bb543847 MRL |
954 | sctp_transport_reset_t3_rtx(ctx->transport); |
955 | ctx->transport->last_time_sent = jiffies; | |
2e3216cd | 956 | } |
7f9d68ac | 957 | |
e136e965 | 958 | if (chunk == ctx->asoc->strreset_chunk) |
bb543847 | 959 | sctp_transport_reset_reconf_timer(ctx->transport); |
7f9d68ac | 960 | |
1da177e4 LT |
961 | break; |
962 | ||
963 | default: | |
964 | /* We built a chunk with an illegal type! */ | |
965 | BUG(); | |
3ff50b79 | 966 | } |
1da177e4 | 967 | } |
7a0b9df6 MRL |
968 | } |
969 | ||
96e0418e | 970 | /* Returns false if new data shouldn't be sent */ |
bb543847 MRL |
971 | static bool sctp_outq_flush_rtx(struct sctp_flush_ctx *ctx, |
972 | int rtx_timeout) | |
96e0418e | 973 | { |
96e0418e MRL |
974 | int error, start_timer = 0; |
975 | ||
e136e965 | 976 | if (ctx->asoc->peer.retran_path->state == SCTP_UNCONFIRMED) |
96e0418e MRL |
977 | return false; |
978 | ||
e136e965 | 979 | if (ctx->transport != ctx->asoc->peer.retran_path) { |
96e0418e | 980 | /* Switch transports & prepare the packet. */ |
e136e965 MRL |
981 | ctx->transport = ctx->asoc->peer.retran_path; |
982 | ctx->packet = &ctx->transport->packet; | |
96e0418e | 983 | |
bb543847 MRL |
984 | if (list_empty(&ctx->transport->send_ready)) |
985 | list_add_tail(&ctx->transport->send_ready, | |
986 | &ctx->transport_list); | |
96e0418e | 987 | |
e136e965 MRL |
988 | sctp_packet_config(ctx->packet, ctx->asoc->peer.i.init_tag, |
989 | ctx->asoc->peer.ecn_capable); | |
96e0418e MRL |
990 | } |
991 | ||
e136e965 MRL |
992 | error = __sctp_outq_flush_rtx(ctx->q, ctx->packet, rtx_timeout, |
993 | &start_timer, ctx->gfp); | |
96e0418e | 994 | if (error < 0) |
e136e965 | 995 | ctx->asoc->base.sk->sk_err = -error; |
96e0418e MRL |
996 | |
997 | if (start_timer) { | |
bb543847 MRL |
998 | sctp_transport_reset_t3_rtx(ctx->transport); |
999 | ctx->transport->last_time_sent = jiffies; | |
96e0418e MRL |
1000 | } |
1001 | ||
1002 | /* This can happen on COOKIE-ECHO resend. Only | |
1003 | * one chunk can get bundled with a COOKIE-ECHO. | |
1004 | */ | |
e136e965 | 1005 | if (ctx->packet->has_cookie_echo) |
96e0418e MRL |
1006 | return false; |
1007 | ||
1008 | /* Don't send new data if there is still data | |
1009 | * waiting to retransmit. | |
1010 | */ | |
bb543847 | 1011 | if (!list_empty(&ctx->q->retransmit)) |
96e0418e MRL |
1012 | return false; |
1013 | ||
1014 | return true; | |
1015 | } | |
cb93cc5d | 1016 | |
bb543847 MRL |
1017 | static void sctp_outq_flush_data(struct sctp_flush_ctx *ctx, |
1018 | int rtx_timeout) | |
7a0b9df6 | 1019 | { |
7a0b9df6 MRL |
1020 | struct sctp_chunk *chunk; |
1021 | enum sctp_xmit status; | |
8a07eb0a | 1022 | |
1da177e4 | 1023 | /* Is it OK to send data chunks? */ |
e136e965 | 1024 | switch (ctx->asoc->state) { |
1da177e4 LT |
1025 | case SCTP_STATE_COOKIE_ECHOED: |
1026 | /* Only allow bundling when this packet has a COOKIE-ECHO | |
1027 | * chunk. | |
1028 | */ | |
e136e965 | 1029 | if (!ctx->packet || !ctx->packet->has_cookie_echo) |
4fdbb0ef | 1030 | return; |
1da177e4 | 1031 | |
2cc543f5 | 1032 | /* fall through */ |
1da177e4 LT |
1033 | case SCTP_STATE_ESTABLISHED: |
1034 | case SCTP_STATE_SHUTDOWN_PENDING: | |
1035 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
4fdbb0ef | 1036 | break; |
1da177e4 | 1037 | |
4fdbb0ef MRL |
1038 | default: |
1039 | /* Do nothing. */ | |
1040 | return; | |
1041 | } | |
1da177e4 | 1042 | |
5884f35f | 1043 | /* RFC 2960 6.1 Transmission of DATA Chunks |
4fdbb0ef MRL |
1044 | * |
1045 | * C) When the time comes for the sender to transmit, | |
1046 | * before sending new DATA chunks, the sender MUST | |
1047 | * first transmit any outstanding DATA chunks which | |
1048 | * are marked for retransmission (limited by the | |
1049 | * current cwnd). | |
1050 | */ | |
e136e965 MRL |
1051 | if (!list_empty(&ctx->q->retransmit) && |
1052 | !sctp_outq_flush_rtx(ctx, rtx_timeout)) | |
1053 | return; | |
7f9d68ac | 1054 | |
4fdbb0ef MRL |
1055 | /* Apply Max.Burst limitation to the current transport in |
1056 | * case it will be used for new data. We are going to | |
1057 | * rest it before we return, but we want to apply the limit | |
1058 | * to the currently queued data. | |
1059 | */ | |
bb543847 MRL |
1060 | if (ctx->transport) |
1061 | sctp_transport_burst_limited(ctx->transport); | |
1da177e4 | 1062 | |
4fdbb0ef | 1063 | /* Finally, transmit new packets. */ |
bb543847 | 1064 | while ((chunk = sctp_outq_dequeue_data(ctx->q)) != NULL) { |
4fdbb0ef | 1065 | __u32 sid = ntohs(chunk->subh.data_hdr->stream); |
05364ca0 | 1066 | __u8 stream_state = SCTP_SO(&ctx->asoc->stream, sid)->state; |
cb93cc5d | 1067 | |
4fdbb0ef MRL |
1068 | /* Has this chunk expired? */ |
1069 | if (sctp_chunk_abandoned(chunk)) { | |
bb543847 | 1070 | sctp_sched_dequeue_done(ctx->q, chunk); |
4fdbb0ef MRL |
1071 | sctp_chunk_fail(chunk, 0); |
1072 | sctp_chunk_free(chunk); | |
1073 | continue; | |
1074 | } | |
bb33381d | 1075 | |
05364ca0 | 1076 | if (stream_state == SCTP_STREAM_CLOSED) { |
bb543847 | 1077 | sctp_outq_head_data(ctx->q, chunk); |
4fdbb0ef MRL |
1078 | break; |
1079 | } | |
1da177e4 | 1080 | |
e136e965 | 1081 | sctp_outq_select_transport(ctx, chunk); |
cb93cc5d | 1082 | |
5884f35f | 1083 | pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p skb->users:%d\n", |
bb543847 | 1084 | __func__, ctx->q, chunk, chunk && chunk->chunk_hdr ? |
4fdbb0ef MRL |
1085 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) : |
1086 | "illegal chunk", ntohl(chunk->subh.data_hdr->tsn), | |
1087 | chunk->skb ? chunk->skb->head : NULL, chunk->skb ? | |
1088 | refcount_read(&chunk->skb->users) : -1); | |
1089 | ||
1090 | /* Add the chunk to the packet. */ | |
e136e965 MRL |
1091 | status = sctp_packet_transmit_chunk(ctx->packet, chunk, 0, |
1092 | ctx->gfp); | |
4fdbb0ef MRL |
1093 | if (status != SCTP_XMIT_OK) { |
1094 | /* We could not append this chunk, so put | |
1095 | * the chunk back on the output queue. | |
cb93cc5d | 1096 | */ |
4fdbb0ef MRL |
1097 | pr_debug("%s: could not transmit tsn:0x%x, status:%d\n", |
1098 | __func__, ntohl(chunk->subh.data_hdr->tsn), | |
1099 | status); | |
1100 | ||
bb543847 | 1101 | sctp_outq_head_data(ctx->q, chunk); |
4fdbb0ef MRL |
1102 | break; |
1103 | } | |
cb93cc5d | 1104 | |
4fdbb0ef MRL |
1105 | /* The sender is in the SHUTDOWN-PENDING state, |
1106 | * The sender MAY set the I-bit in the DATA | |
1107 | * chunk header. | |
1108 | */ | |
e136e965 | 1109 | if (ctx->asoc->state == SCTP_STATE_SHUTDOWN_PENDING) |
4fdbb0ef MRL |
1110 | chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; |
1111 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
e136e965 | 1112 | ctx->asoc->stats.ouodchunks++; |
4fdbb0ef | 1113 | else |
e136e965 | 1114 | ctx->asoc->stats.oodchunks++; |
1da177e4 | 1115 | |
4fdbb0ef MRL |
1116 | /* Only now it's safe to consider this |
1117 | * chunk as sent, sched-wise. | |
1118 | */ | |
bb543847 | 1119 | sctp_sched_dequeue_done(ctx->q, chunk); |
1da177e4 | 1120 | |
4fdbb0ef | 1121 | list_add_tail(&chunk->transmitted_list, |
bb543847 | 1122 | &ctx->transport->transmitted); |
1da177e4 | 1123 | |
bb543847 MRL |
1124 | sctp_transport_reset_t3_rtx(ctx->transport); |
1125 | ctx->transport->last_time_sent = jiffies; | |
4fdbb0ef MRL |
1126 | |
1127 | /* Only let one DATA chunk get bundled with a | |
1128 | * COOKIE-ECHO chunk. | |
1129 | */ | |
e136e965 | 1130 | if (ctx->packet->has_cookie_echo) |
4fdbb0ef | 1131 | break; |
1da177e4 | 1132 | } |
cb93cc5d MRL |
1133 | } |
1134 | ||
bb543847 | 1135 | static void sctp_outq_flush_transports(struct sctp_flush_ctx *ctx) |
4bf21b61 MRL |
1136 | { |
1137 | struct list_head *ltransport; | |
1138 | struct sctp_packet *packet; | |
1139 | struct sctp_transport *t; | |
1140 | int error = 0; | |
1141 | ||
bb543847 | 1142 | while ((ltransport = sctp_list_dequeue(&ctx->transport_list)) != NULL) { |
4bf21b61 MRL |
1143 | t = list_entry(ltransport, struct sctp_transport, send_ready); |
1144 | packet = &t->packet; | |
1145 | if (!sctp_packet_empty(packet)) { | |
bb543847 | 1146 | error = sctp_packet_transmit(packet, ctx->gfp); |
4bf21b61 | 1147 | if (error < 0) |
bb543847 | 1148 | ctx->q->asoc->base.sk->sk_err = -error; |
4bf21b61 MRL |
1149 | } |
1150 | ||
1151 | /* Clear the burst limited state, if any */ | |
1152 | sctp_transport_burst_reset(t); | |
1153 | } | |
1154 | } | |
1155 | ||
5884f35f | 1156 | /* Try to flush an outqueue. |
cb93cc5d MRL |
1157 | * |
1158 | * Description: Send everything in q which we legally can, subject to | |
1159 | * congestion limitations. | |
1160 | * * Note: This function can be called from multiple contexts so appropriate | |
1161 | * locking concerns must be made. Today we use the sock lock to protect | |
1162 | * this function. | |
1163 | */ | |
bb543847 | 1164 | |
cb93cc5d MRL |
1165 | static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp) |
1166 | { | |
bb543847 MRL |
1167 | struct sctp_flush_ctx ctx = { |
1168 | .q = q, | |
1169 | .transport = NULL, | |
1170 | .transport_list = LIST_HEAD_INIT(ctx.transport_list), | |
e136e965 MRL |
1171 | .asoc = q->asoc, |
1172 | .packet = NULL, | |
bb543847 MRL |
1173 | .gfp = gfp, |
1174 | }; | |
cb93cc5d | 1175 | |
5884f35f | 1176 | /* 6.10 Bundling |
cb93cc5d MRL |
1177 | * ... |
1178 | * When bundling control chunks with DATA chunks, an | |
1179 | * endpoint MUST place control chunks first in the outbound | |
1180 | * SCTP packet. The transmitter MUST transmit DATA chunks | |
1181 | * within a SCTP packet in increasing order of TSN. | |
1182 | * ... | |
1183 | */ | |
1184 | ||
bb543847 | 1185 | sctp_outq_flush_ctrl(&ctx); |
cb93cc5d MRL |
1186 | |
1187 | if (q->asoc->src_out_of_asoc_ok) | |
1188 | goto sctp_flush_out; | |
1189 | ||
bb543847 | 1190 | sctp_outq_flush_data(&ctx, rtx_timeout); |
1da177e4 LT |
1191 | |
1192 | sctp_flush_out: | |
1193 | ||
bb543847 | 1194 | sctp_outq_flush_transports(&ctx); |
1da177e4 LT |
1195 | } |
1196 | ||
1197 | /* Update unack_data based on the incoming SACK chunk */ | |
1198 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, | |
1199 | struct sctp_sackhdr *sack) | |
1200 | { | |
afd93b7b | 1201 | union sctp_sack_variable *frags; |
1da177e4 LT |
1202 | __u16 unack_data; |
1203 | int i; | |
1204 | ||
1205 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; | |
1206 | ||
1207 | frags = sack->variable; | |
1208 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { | |
1209 | unack_data -= ((ntohs(frags[i].gab.end) - | |
1210 | ntohs(frags[i].gab.start) + 1)); | |
1211 | } | |
1212 | ||
1213 | assoc->unack_data = unack_data; | |
1214 | } | |
1215 | ||
1da177e4 LT |
1216 | /* This is where we REALLY process a SACK. |
1217 | * | |
1218 | * Process the SACK against the outqueue. Mostly, this just frees | |
1219 | * things off the transmitted queue. | |
1220 | */ | |
edfee033 | 1221 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk) |
1da177e4 LT |
1222 | { |
1223 | struct sctp_association *asoc = q->asoc; | |
edfee033 | 1224 | struct sctp_sackhdr *sack = chunk->subh.sack_hdr; |
1da177e4 LT |
1225 | struct sctp_transport *transport; |
1226 | struct sctp_chunk *tchunk = NULL; | |
9dbc15f0 | 1227 | struct list_head *lchunk, *transport_list, *temp; |
afd93b7b | 1228 | union sctp_sack_variable *frags = sack->variable; |
1da177e4 LT |
1229 | __u32 sack_ctsn, ctsn, tsn; |
1230 | __u32 highest_tsn, highest_new_tsn; | |
1231 | __u32 sack_a_rwnd; | |
95c96174 | 1232 | unsigned int outstanding; |
1da177e4 LT |
1233 | struct sctp_transport *primary = asoc->peer.primary_path; |
1234 | int count_of_newacks = 0; | |
2cd9b822 | 1235 | int gap_ack_blocks; |
ea862c8d | 1236 | u8 accum_moved = 0; |
1da177e4 LT |
1237 | |
1238 | /* Grab the association's destination address list. */ | |
1239 | transport_list = &asoc->peer.transport_addr_list; | |
1240 | ||
1241 | sack_ctsn = ntohl(sack->cum_tsn_ack); | |
2cd9b822 | 1242 | gap_ack_blocks = ntohs(sack->num_gap_ack_blocks); |
196d6759 | 1243 | asoc->stats.gapcnt += gap_ack_blocks; |
1da177e4 LT |
1244 | /* |
1245 | * SFR-CACC algorithm: | |
1246 | * On receipt of a SACK the sender SHOULD execute the | |
1247 | * following statements. | |
1248 | * | |
1249 | * 1) If the cumulative ack in the SACK passes next tsn_at_change | |
1250 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be | |
1251 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for | |
1252 | * all destinations. | |
1da177e4 LT |
1253 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
1254 | * is set the receiver of the SACK MUST take the following actions: | |
1255 | * | |
1256 | * A) Initialize the cacc_saw_newack to 0 for all destination | |
1257 | * addresses. | |
ab5216a5 VY |
1258 | * |
1259 | * Only bother if changeover_active is set. Otherwise, this is | |
1260 | * totally suboptimal to do on every SACK. | |
1da177e4 | 1261 | */ |
ab5216a5 VY |
1262 | if (primary->cacc.changeover_active) { |
1263 | u8 clear_cycling = 0; | |
1264 | ||
1265 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { | |
1266 | primary->cacc.changeover_active = 0; | |
1267 | clear_cycling = 1; | |
1268 | } | |
1269 | ||
1270 | if (clear_cycling || gap_ack_blocks) { | |
1271 | list_for_each_entry(transport, transport_list, | |
1272 | transports) { | |
1273 | if (clear_cycling) | |
1274 | transport->cacc.cycling_changeover = 0; | |
1275 | if (gap_ack_blocks) | |
1276 | transport->cacc.cacc_saw_newack = 0; | |
1277 | } | |
1da177e4 LT |
1278 | } |
1279 | } | |
1280 | ||
1281 | /* Get the highest TSN in the sack. */ | |
1282 | highest_tsn = sack_ctsn; | |
2cd9b822 VY |
1283 | if (gap_ack_blocks) |
1284 | highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); | |
1da177e4 | 1285 | |
bfa0d984 | 1286 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) |
1da177e4 | 1287 | asoc->highest_sacked = highest_tsn; |
1da177e4 | 1288 | |
bfa0d984 | 1289 | highest_new_tsn = sack_ctsn; |
2cd9b822 | 1290 | |
1da177e4 LT |
1291 | /* Run through the retransmit queue. Credit bytes received |
1292 | * and free those chunks that we can. | |
1293 | */ | |
edfee033 | 1294 | sctp_check_transmitted(q, &q->retransmit, NULL, NULL, sack, &highest_new_tsn); |
1da177e4 LT |
1295 | |
1296 | /* Run through the transmitted queue. | |
1297 | * Credit bytes received and free those chunks which we can. | |
1298 | * | |
1299 | * This is a MASSIVE candidate for optimization. | |
1300 | */ | |
9dbc15f0 | 1301 | list_for_each_entry(transport, transport_list, transports) { |
1da177e4 | 1302 | sctp_check_transmitted(q, &transport->transmitted, |
edfee033 ND |
1303 | transport, &chunk->source, sack, |
1304 | &highest_new_tsn); | |
1da177e4 LT |
1305 | /* |
1306 | * SFR-CACC algorithm: | |
1307 | * C) Let count_of_newacks be the number of | |
1308 | * destinations for which cacc_saw_newack is set. | |
1309 | */ | |
1310 | if (transport->cacc.cacc_saw_newack) | |
cb3f837b | 1311 | count_of_newacks++; |
1da177e4 LT |
1312 | } |
1313 | ||
ea862c8d VY |
1314 | /* Move the Cumulative TSN Ack Point if appropriate. */ |
1315 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) { | |
1316 | asoc->ctsn_ack_point = sack_ctsn; | |
1317 | accum_moved = 1; | |
1318 | } | |
1319 | ||
2cd9b822 | 1320 | if (gap_ack_blocks) { |
ea862c8d VY |
1321 | |
1322 | if (asoc->fast_recovery && accum_moved) | |
1323 | highest_new_tsn = highest_tsn; | |
1324 | ||
2cd9b822 VY |
1325 | list_for_each_entry(transport, transport_list, transports) |
1326 | sctp_mark_missing(q, &transport->transmitted, transport, | |
1327 | highest_new_tsn, count_of_newacks); | |
1da177e4 LT |
1328 | } |
1329 | ||
1da177e4 LT |
1330 | /* Update unack_data field in the assoc. */ |
1331 | sctp_sack_update_unack_data(asoc, sack); | |
1332 | ||
1333 | ctsn = asoc->ctsn_ack_point; | |
1334 | ||
1335 | /* Throw away stuff rotting on the sack queue. */ | |
1336 | list_for_each_safe(lchunk, temp, &q->sacked) { | |
1337 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1338 | transmitted_list); | |
1339 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
5f9646c3 VY |
1340 | if (TSN_lte(tsn, ctsn)) { |
1341 | list_del_init(&tchunk->transmitted_list); | |
be4947bf | 1342 | if (asoc->peer.prsctp_capable && |
8dbdf1f5 XL |
1343 | SCTP_PR_PRIO_ENABLED(chunk->sinfo.sinfo_flags)) |
1344 | asoc->sent_cnt_removable--; | |
1da177e4 | 1345 | sctp_chunk_free(tchunk); |
5f9646c3 | 1346 | } |
1da177e4 LT |
1347 | } |
1348 | ||
1349 | /* ii) Set rwnd equal to the newly received a_rwnd minus the | |
1350 | * number of bytes still outstanding after processing the | |
1351 | * Cumulative TSN Ack and the Gap Ack Blocks. | |
1352 | */ | |
1353 | ||
1354 | sack_a_rwnd = ntohl(sack->a_rwnd); | |
8a0d19c5 | 1355 | asoc->peer.zero_window_announced = !sack_a_rwnd; |
1da177e4 LT |
1356 | outstanding = q->outstanding_bytes; |
1357 | ||
1358 | if (outstanding < sack_a_rwnd) | |
1359 | sack_a_rwnd -= outstanding; | |
1360 | else | |
1361 | sack_a_rwnd = 0; | |
1362 | ||
1363 | asoc->peer.rwnd = sack_a_rwnd; | |
1364 | ||
8e0c3b73 | 1365 | asoc->stream.si->generate_ftsn(q, sack_ctsn); |
1da177e4 | 1366 | |
bb33381d DB |
1367 | pr_debug("%s: sack cumulative tsn ack:0x%x\n", __func__, sack_ctsn); |
1368 | pr_debug("%s: cumulative tsn ack of assoc:%p is 0x%x, " | |
1369 | "advertised peer ack point:0x%x\n", __func__, asoc, ctsn, | |
1370 | asoc->adv_peer_ack_point); | |
1da177e4 | 1371 | |
619a60ee | 1372 | return sctp_outq_is_empty(q); |
1da177e4 LT |
1373 | } |
1374 | ||
619a60ee VY |
1375 | /* Is the outqueue empty? |
1376 | * The queue is empty when we have not pending data, no in-flight data | |
1377 | * and nothing pending retransmissions. | |
1378 | */ | |
1da177e4 LT |
1379 | int sctp_outq_is_empty(const struct sctp_outq *q) |
1380 | { | |
619a60ee VY |
1381 | return q->out_qlen == 0 && q->outstanding_bytes == 0 && |
1382 | list_empty(&q->retransmit); | |
1da177e4 LT |
1383 | } |
1384 | ||
1385 | /******************************************************************** | |
1386 | * 2nd Level Abstractions | |
1387 | ********************************************************************/ | |
1388 | ||
1389 | /* Go through a transport's transmitted list or the association's retransmit | |
1390 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. | |
1391 | * The retransmit list will not have an associated transport. | |
1392 | * | |
1393 | * I added coherent debug information output. --xguo | |
1394 | * | |
1395 | * Instead of printing 'sacked' or 'kept' for each TSN on the | |
1396 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. | |
1397 | * KEPT TSN6-TSN7, etc. | |
1398 | */ | |
1399 | static void sctp_check_transmitted(struct sctp_outq *q, | |
1400 | struct list_head *transmitted_queue, | |
1401 | struct sctp_transport *transport, | |
edfee033 | 1402 | union sctp_addr *saddr, |
1da177e4 | 1403 | struct sctp_sackhdr *sack, |
bfa0d984 | 1404 | __u32 *highest_new_tsn_in_sack) |
1da177e4 LT |
1405 | { |
1406 | struct list_head *lchunk; | |
1407 | struct sctp_chunk *tchunk; | |
1408 | struct list_head tlist; | |
1409 | __u32 tsn; | |
1410 | __u32 sack_ctsn; | |
1411 | __u32 rtt; | |
1412 | __u8 restart_timer = 0; | |
1413 | int bytes_acked = 0; | |
31b02e15 | 1414 | int migrate_bytes = 0; |
8c2f414a | 1415 | bool forward_progress = false; |
1da177e4 | 1416 | |
1da177e4 LT |
1417 | sack_ctsn = ntohl(sack->cum_tsn_ack); |
1418 | ||
1419 | INIT_LIST_HEAD(&tlist); | |
1420 | ||
1421 | /* The while loop will skip empty transmitted queues. */ | |
1422 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { | |
1423 | tchunk = list_entry(lchunk, struct sctp_chunk, | |
1424 | transmitted_list); | |
1425 | ||
1426 | if (sctp_chunk_abandoned(tchunk)) { | |
1427 | /* Move the chunk to abandoned list. */ | |
1428 | sctp_insert_list(&q->abandoned, lchunk); | |
8c4a2d41 VY |
1429 | |
1430 | /* If this chunk has not been acked, stop | |
1431 | * considering it as 'outstanding'. | |
1432 | */ | |
d30fc512 XL |
1433 | if (transmitted_queue != &q->retransmit && |
1434 | !tchunk->tsn_gap_acked) { | |
31b02e15 VY |
1435 | if (tchunk->transport) |
1436 | tchunk->transport->flight_size -= | |
1437 | sctp_data_size(tchunk); | |
8c4a2d41 VY |
1438 | q->outstanding_bytes -= sctp_data_size(tchunk); |
1439 | } | |
1da177e4 LT |
1440 | continue; |
1441 | } | |
1442 | ||
1443 | tsn = ntohl(tchunk->subh.data_hdr->tsn); | |
1444 | if (sctp_acked(sack, tsn)) { | |
1445 | /* If this queue is the retransmit queue, the | |
1446 | * retransmit timer has already reclaimed | |
1447 | * the outstanding bytes for this chunk, so only | |
1448 | * count bytes associated with a transport. | |
1449 | */ | |
51446780 | 1450 | if (transport && !tchunk->tsn_gap_acked) { |
1da177e4 LT |
1451 | /* If this chunk is being used for RTT |
1452 | * measurement, calculate the RTT and update | |
1453 | * the RTO using this value. | |
1454 | * | |
1455 | * 6.3.1 C5) Karn's algorithm: RTT measurements | |
1456 | * MUST NOT be made using packets that were | |
1457 | * retransmitted (and thus for which it is | |
1458 | * ambiguous whether the reply was for the | |
1459 | * first instance of the packet or a later | |
1460 | * instance). | |
1461 | */ | |
51446780 | 1462 | if (!sctp_chunk_retransmitted(tchunk) && |
1da177e4 | 1463 | tchunk->rtt_in_progress) { |
4c9f5d53 | 1464 | tchunk->rtt_in_progress = 0; |
1da177e4 LT |
1465 | rtt = jiffies - tchunk->sent_at; |
1466 | sctp_transport_update_rto(transport, | |
1467 | rtt); | |
1468 | } | |
51446780 MRL |
1469 | |
1470 | if (TSN_lte(tsn, sack_ctsn)) { | |
1471 | /* | |
1472 | * SFR-CACC algorithm: | |
1473 | * 2) If the SACK contains gap acks | |
1474 | * and the flag CHANGEOVER_ACTIVE is | |
1475 | * set the receiver of the SACK MUST | |
1476 | * take the following action: | |
1477 | * | |
1478 | * B) For each TSN t being acked that | |
1479 | * has not been acked in any SACK so | |
1480 | * far, set cacc_saw_newack to 1 for | |
1481 | * the destination that the TSN was | |
1482 | * sent to. | |
1483 | */ | |
1484 | if (sack->num_gap_ack_blocks && | |
1485 | q->asoc->peer.primary_path->cacc. | |
1486 | changeover_active) | |
1487 | transport->cacc.cacc_saw_newack | |
1488 | = 1; | |
1489 | } | |
1da177e4 | 1490 | } |
31b02e15 VY |
1491 | |
1492 | /* If the chunk hasn't been marked as ACKED, | |
1493 | * mark it and account bytes_acked if the | |
1494 | * chunk had a valid transport (it will not | |
1495 | * have a transport if ASCONF had deleted it | |
1496 | * while DATA was outstanding). | |
1497 | */ | |
1498 | if (!tchunk->tsn_gap_acked) { | |
1499 | tchunk->tsn_gap_acked = 1; | |
d6c41614 CX |
1500 | if (TSN_lt(*highest_new_tsn_in_sack, tsn)) |
1501 | *highest_new_tsn_in_sack = tsn; | |
31b02e15 VY |
1502 | bytes_acked += sctp_data_size(tchunk); |
1503 | if (!tchunk->transport) | |
1504 | migrate_bytes += sctp_data_size(tchunk); | |
8c2f414a | 1505 | forward_progress = true; |
31b02e15 VY |
1506 | } |
1507 | ||
d808ad9a | 1508 | if (TSN_lte(tsn, sack_ctsn)) { |
1da177e4 LT |
1509 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
1510 | * | |
1511 | * R3) Whenever a SACK is received | |
1512 | * that acknowledges the DATA chunk | |
1513 | * with the earliest outstanding TSN | |
1514 | * for that address, restart T3-rtx | |
1515 | * timer for that address with its | |
1516 | * current RTO. | |
1517 | */ | |
1518 | restart_timer = 1; | |
8c2f414a | 1519 | forward_progress = true; |
1da177e4 | 1520 | |
1da177e4 LT |
1521 | list_add_tail(&tchunk->transmitted_list, |
1522 | &q->sacked); | |
1523 | } else { | |
1524 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 | |
1525 | * M2) Each time a SACK arrives reporting | |
1526 | * 'Stray DATA chunk(s)' record the highest TSN | |
1527 | * reported as newly acknowledged, call this | |
1528 | * value 'HighestTSNinSack'. A newly | |
1529 | * acknowledged DATA chunk is one not | |
1530 | * previously acknowledged in a SACK. | |
1531 | * | |
1532 | * When the SCTP sender of data receives a SACK | |
1533 | * chunk that acknowledges, for the first time, | |
1534 | * the receipt of a DATA chunk, all the still | |
1535 | * unacknowledged DATA chunks whose TSN is | |
1536 | * older than that newly acknowledged DATA | |
1537 | * chunk, are qualified as 'Stray DATA chunks'. | |
1538 | */ | |
1da177e4 LT |
1539 | list_add_tail(lchunk, &tlist); |
1540 | } | |
1da177e4 LT |
1541 | } else { |
1542 | if (tchunk->tsn_gap_acked) { | |
bb33381d DB |
1543 | pr_debug("%s: receiver reneged on data TSN:0x%x\n", |
1544 | __func__, tsn); | |
1545 | ||
1da177e4 LT |
1546 | tchunk->tsn_gap_acked = 0; |
1547 | ||
31b02e15 VY |
1548 | if (tchunk->transport) |
1549 | bytes_acked -= sctp_data_size(tchunk); | |
1da177e4 LT |
1550 | |
1551 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1552 | * | |
1553 | * R4) Whenever a SACK is received missing a | |
1554 | * TSN that was previously acknowledged via a | |
1555 | * Gap Ack Block, start T3-rtx for the | |
1556 | * destination address to which the DATA | |
1557 | * chunk was originally | |
1558 | * transmitted if it is not already running. | |
1559 | */ | |
1560 | restart_timer = 1; | |
1561 | } | |
1562 | ||
1563 | list_add_tail(lchunk, &tlist); | |
1da177e4 LT |
1564 | } |
1565 | } | |
1566 | ||
1da177e4 LT |
1567 | if (transport) { |
1568 | if (bytes_acked) { | |
f8d96052 TG |
1569 | struct sctp_association *asoc = transport->asoc; |
1570 | ||
31b02e15 VY |
1571 | /* We may have counted DATA that was migrated |
1572 | * to this transport due to DEL-IP operation. | |
1573 | * Subtract those bytes, since the were never | |
1574 | * send on this transport and shouldn't be | |
1575 | * credited to this transport. | |
1576 | */ | |
1577 | bytes_acked -= migrate_bytes; | |
1578 | ||
1da177e4 LT |
1579 | /* 8.2. When an outstanding TSN is acknowledged, |
1580 | * the endpoint shall clear the error counter of | |
1581 | * the destination transport address to which the | |
1582 | * DATA chunk was last sent. | |
1583 | * The association's overall error counter is | |
1584 | * also cleared. | |
1585 | */ | |
1586 | transport->error_count = 0; | |
1587 | transport->asoc->overall_error_count = 0; | |
8c2f414a | 1588 | forward_progress = true; |
1da177e4 | 1589 | |
f8d96052 TG |
1590 | /* |
1591 | * While in SHUTDOWN PENDING, we may have started | |
1592 | * the T5 shutdown guard timer after reaching the | |
1593 | * retransmission limit. Stop that timer as soon | |
1594 | * as the receiver acknowledged any data. | |
1595 | */ | |
1596 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING && | |
1597 | del_timer(&asoc->timers | |
1598 | [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD])) | |
1599 | sctp_association_put(asoc); | |
1600 | ||
1da177e4 LT |
1601 | /* Mark the destination transport address as |
1602 | * active if it is not so marked. | |
1603 | */ | |
edfee033 ND |
1604 | if ((transport->state == SCTP_INACTIVE || |
1605 | transport->state == SCTP_UNCONFIRMED) && | |
1606 | sctp_cmp_addr_exact(&transport->ipaddr, saddr)) { | |
1da177e4 LT |
1607 | sctp_assoc_control_transport( |
1608 | transport->asoc, | |
1609 | transport, | |
1610 | SCTP_TRANSPORT_UP, | |
1611 | SCTP_RECEIVED_SACK); | |
1612 | } | |
1613 | ||
1614 | sctp_transport_raise_cwnd(transport, sack_ctsn, | |
1615 | bytes_acked); | |
1616 | ||
1617 | transport->flight_size -= bytes_acked; | |
8b73a07c GJ |
1618 | if (transport->flight_size == 0) |
1619 | transport->partial_bytes_acked = 0; | |
31b02e15 | 1620 | q->outstanding_bytes -= bytes_acked + migrate_bytes; |
1da177e4 LT |
1621 | } else { |
1622 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 | |
1623 | * When a sender is doing zero window probing, it | |
1624 | * should not timeout the association if it continues | |
1625 | * to receive new packets from the receiver. The | |
1626 | * reason is that the receiver MAY keep its window | |
1627 | * closed for an indefinite time. | |
1628 | * A sender is doing zero window probing when the | |
1629 | * receiver's advertised window is zero, and there is | |
1630 | * only one data chunk in flight to the receiver. | |
f8d96052 TG |
1631 | * |
1632 | * Allow the association to timeout while in SHUTDOWN | |
1633 | * PENDING or SHUTDOWN RECEIVED in case the receiver | |
1634 | * stays in zero window mode forever. | |
1da177e4 LT |
1635 | */ |
1636 | if (!q->asoc->peer.rwnd && | |
1637 | !list_empty(&tlist) && | |
f8d96052 TG |
1638 | (sack_ctsn+2 == q->asoc->next_tsn) && |
1639 | q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) { | |
bb33381d DB |
1640 | pr_debug("%s: sack received for zero window " |
1641 | "probe:%u\n", __func__, sack_ctsn); | |
1642 | ||
1da177e4 LT |
1643 | q->asoc->overall_error_count = 0; |
1644 | transport->error_count = 0; | |
1645 | } | |
1646 | } | |
1647 | ||
1648 | /* RFC 2960 6.3.2 Retransmission Timer Rules | |
1649 | * | |
1650 | * R2) Whenever all outstanding data sent to an address have | |
1651 | * been acknowledged, turn off the T3-rtx timer of that | |
1652 | * address. | |
1653 | */ | |
1654 | if (!transport->flight_size) { | |
25cc4ae9 | 1655 | if (del_timer(&transport->T3_rtx_timer)) |
1da177e4 | 1656 | sctp_transport_put(transport); |
1da177e4 LT |
1657 | } else if (restart_timer) { |
1658 | if (!mod_timer(&transport->T3_rtx_timer, | |
1659 | jiffies + transport->rto)) | |
1660 | sctp_transport_hold(transport); | |
1661 | } | |
8c2f414a DB |
1662 | |
1663 | if (forward_progress) { | |
1664 | if (transport->dst) | |
c86a773c | 1665 | sctp_transport_dst_confirm(transport); |
8c2f414a | 1666 | } |
1da177e4 LT |
1667 | } |
1668 | ||
1669 | list_splice(&tlist, transmitted_queue); | |
1670 | } | |
1671 | ||
1672 | /* Mark chunks as missing and consequently may get retransmitted. */ | |
1673 | static void sctp_mark_missing(struct sctp_outq *q, | |
1674 | struct list_head *transmitted_queue, | |
1675 | struct sctp_transport *transport, | |
1676 | __u32 highest_new_tsn_in_sack, | |
1677 | int count_of_newacks) | |
1678 | { | |
1679 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1680 | __u32 tsn; |
1681 | char do_fast_retransmit = 0; | |
ea862c8d VY |
1682 | struct sctp_association *asoc = q->asoc; |
1683 | struct sctp_transport *primary = asoc->peer.primary_path; | |
1da177e4 | 1684 | |
9dbc15f0 | 1685 | list_for_each_entry(chunk, transmitted_queue, transmitted_list) { |
1da177e4 | 1686 | |
1da177e4 LT |
1687 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
1688 | ||
1689 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all | |
1690 | * 'Unacknowledged TSN's', if the TSN number of an | |
1691 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' | |
1692 | * value, increment the 'TSN.Missing.Report' count on that | |
1693 | * chunk if it has NOT been fast retransmitted or marked for | |
1694 | * fast retransmit already. | |
1695 | */ | |
c226ef9b | 1696 | if (chunk->fast_retransmit == SCTP_CAN_FRTX && |
1da177e4 LT |
1697 | !chunk->tsn_gap_acked && |
1698 | TSN_lt(tsn, highest_new_tsn_in_sack)) { | |
1699 | ||
1700 | /* SFR-CACC may require us to skip marking | |
1701 | * this chunk as missing. | |
1702 | */ | |
f246a7b7 VY |
1703 | if (!transport || !sctp_cacc_skip(primary, |
1704 | chunk->transport, | |
1705 | count_of_newacks, tsn)) { | |
1da177e4 LT |
1706 | chunk->tsn_missing_report++; |
1707 | ||
bb33381d DB |
1708 | pr_debug("%s: tsn:0x%x missing counter:%d\n", |
1709 | __func__, tsn, chunk->tsn_missing_report); | |
1da177e4 LT |
1710 | } |
1711 | } | |
1712 | /* | |
1713 | * M4) If any DATA chunk is found to have a | |
1714 | * 'TSN.Missing.Report' | |
27852c26 | 1715 | * value larger than or equal to 3, mark that chunk for |
1da177e4 LT |
1716 | * retransmission and start the fast retransmit procedure. |
1717 | */ | |
1718 | ||
27852c26 | 1719 | if (chunk->tsn_missing_report >= 3) { |
c226ef9b | 1720 | chunk->fast_retransmit = SCTP_NEED_FRTX; |
1da177e4 LT |
1721 | do_fast_retransmit = 1; |
1722 | } | |
1723 | } | |
1724 | ||
1725 | if (transport) { | |
1726 | if (do_fast_retransmit) | |
1727 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); | |
1728 | ||
bb33381d DB |
1729 | pr_debug("%s: transport:%p, cwnd:%d, ssthresh:%d, " |
1730 | "flight_size:%d, pba:%d\n", __func__, transport, | |
1731 | transport->cwnd, transport->ssthresh, | |
1732 | transport->flight_size, transport->partial_bytes_acked); | |
1da177e4 LT |
1733 | } |
1734 | } | |
1735 | ||
1736 | /* Is the given TSN acked by this packet? */ | |
1737 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) | |
1738 | { | |
1da177e4 | 1739 | __u32 ctsn = ntohl(sack->cum_tsn_ack); |
afd93b7b XL |
1740 | union sctp_sack_variable *frags; |
1741 | __u16 tsn_offset, blocks; | |
1742 | int i; | |
1da177e4 | 1743 | |
d808ad9a | 1744 | if (TSN_lte(tsn, ctsn)) |
1da177e4 LT |
1745 | goto pass; |
1746 | ||
5884f35f | 1747 | /* 3.3.4 Selective Acknowledgment (SACK) (3): |
1da177e4 LT |
1748 | * |
1749 | * Gap Ack Blocks: | |
1750 | * These fields contain the Gap Ack Blocks. They are repeated | |
1751 | * for each Gap Ack Block up to the number of Gap Ack Blocks | |
1752 | * defined in the Number of Gap Ack Blocks field. All DATA | |
1753 | * chunks with TSNs greater than or equal to (Cumulative TSN | |
1754 | * Ack + Gap Ack Block Start) and less than or equal to | |
1755 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack | |
1756 | * Block are assumed to have been received correctly. | |
1757 | */ | |
1758 | ||
1759 | frags = sack->variable; | |
a3007446 MRL |
1760 | blocks = ntohs(sack->num_gap_ack_blocks); |
1761 | tsn_offset = tsn - ctsn; | |
1762 | for (i = 0; i < blocks; ++i) { | |
1763 | if (tsn_offset >= ntohs(frags[i].gab.start) && | |
1764 | tsn_offset <= ntohs(frags[i].gab.end)) | |
1da177e4 LT |
1765 | goto pass; |
1766 | } | |
1767 | ||
1768 | return 0; | |
1769 | pass: | |
1770 | return 1; | |
1771 | } | |
1772 | ||
1773 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, | |
9f81bcd9 | 1774 | int nskips, __be16 stream) |
1da177e4 LT |
1775 | { |
1776 | int i; | |
1777 | ||
1778 | for (i = 0; i < nskips; i++) { | |
1779 | if (skiplist[i].stream == stream) | |
1780 | return i; | |
1781 | } | |
1782 | return i; | |
1783 | } | |
1784 | ||
1785 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ | |
8e0c3b73 | 1786 | void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) |
1da177e4 LT |
1787 | { |
1788 | struct sctp_association *asoc = q->asoc; | |
1789 | struct sctp_chunk *ftsn_chunk = NULL; | |
1790 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; | |
1791 | int nskips = 0; | |
1792 | int skip_pos = 0; | |
1793 | __u32 tsn; | |
1794 | struct sctp_chunk *chunk; | |
1795 | struct list_head *lchunk, *temp; | |
1796 | ||
76595024 WY |
1797 | if (!asoc->peer.prsctp_capable) |
1798 | return; | |
1799 | ||
1da177e4 LT |
1800 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
1801 | * received SACK. | |
d808ad9a | 1802 | * |
1da177e4 LT |
1803 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
1804 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. | |
1805 | */ | |
1806 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) | |
1807 | asoc->adv_peer_ack_point = ctsn; | |
1808 | ||
1809 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" | |
1810 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as | |
1811 | * the chunk next in the out-queue space is marked as "abandoned" as | |
1812 | * shown in the following example: | |
1813 | * | |
1814 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 | |
1815 | * and the Advanced.Peer.Ack.Point is updated to this value: | |
d808ad9a | 1816 | * |
1da177e4 LT |
1817 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
1818 | * normal SACK processing local advancement | |
1819 | * ... ... | |
1820 | * Adv.Ack.Pt-> 102 acked 102 acked | |
1821 | * 103 abandoned 103 abandoned | |
1822 | * 104 abandoned Adv.Ack.P-> 104 abandoned | |
1823 | * 105 105 | |
1824 | * 106 acked 106 acked | |
1825 | * ... ... | |
1826 | * | |
1827 | * In this example, the data sender successfully advanced the | |
1828 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. | |
1829 | */ | |
1830 | list_for_each_safe(lchunk, temp, &q->abandoned) { | |
1831 | chunk = list_entry(lchunk, struct sctp_chunk, | |
1832 | transmitted_list); | |
1833 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
1834 | ||
1835 | /* Remove any chunks in the abandoned queue that are acked by | |
1836 | * the ctsn. | |
d808ad9a | 1837 | */ |
1da177e4 LT |
1838 | if (TSN_lte(tsn, ctsn)) { |
1839 | list_del_init(lchunk); | |
1da177e4 LT |
1840 | sctp_chunk_free(chunk); |
1841 | } else { | |
1842 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { | |
1843 | asoc->adv_peer_ack_point = tsn; | |
1844 | if (chunk->chunk_hdr->flags & | |
1845 | SCTP_DATA_UNORDERED) | |
1846 | continue; | |
1847 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], | |
1848 | nskips, | |
1849 | chunk->subh.data_hdr->stream); | |
1850 | ftsn_skip_arr[skip_pos].stream = | |
1851 | chunk->subh.data_hdr->stream; | |
1852 | ftsn_skip_arr[skip_pos].ssn = | |
1853 | chunk->subh.data_hdr->ssn; | |
1854 | if (skip_pos == nskips) | |
1855 | nskips++; | |
1856 | if (nskips == 10) | |
1857 | break; | |
1858 | } else | |
1859 | break; | |
1860 | } | |
1861 | } | |
1862 | ||
1863 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" | |
1864 | * is greater than the Cumulative TSN ACK carried in the received | |
1865 | * SACK, the data sender MUST send the data receiver a FORWARD TSN | |
1866 | * chunk containing the latest value of the | |
1867 | * "Advanced.Peer.Ack.Point". | |
1868 | * | |
1869 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD | |
1870 | * list each stream and sequence number in the forwarded TSN. This | |
1871 | * information will enable the receiver to easily find any | |
1872 | * stranded TSN's waiting on stream reorder queues. Each stream | |
1873 | * SHOULD only be reported once; this means that if multiple | |
1874 | * abandoned messages occur in the same stream then only the | |
1875 | * highest abandoned stream sequence number is reported. If the | |
1876 | * total size of the FORWARD TSN does NOT fit in a single MTU then | |
1877 | * the sender of the FORWARD TSN SHOULD lower the | |
1878 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a | |
1879 | * single MTU. | |
1880 | */ | |
1881 | if (asoc->adv_peer_ack_point > ctsn) | |
1882 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, | |
d808ad9a | 1883 | nskips, &ftsn_skip_arr[0]); |
1da177e4 LT |
1884 | |
1885 | if (ftsn_chunk) { | |
79af02c2 | 1886 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
b01a2407 | 1887 | SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS); |
1da177e4 LT |
1888 | } |
1889 | } |