Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* SCTP kernel reference Implementation |
| 2 | * (C) Copyright IBM Corp. 2001, 2004 |
| 3 | * Copyright (c) 1999-2000 Cisco, Inc. |
| 4 | * Copyright (c) 1999-2001 Motorola, Inc. |
| 5 | * Copyright (c) 2001-2003 Intel Corp. |
| 6 | * |
| 7 | * This file is part of the SCTP kernel reference Implementation |
| 8 | * |
| 9 | * These functions implement the sctp_outq class. The outqueue handles |
| 10 | * bundling and queueing of outgoing SCTP chunks. |
| 11 | * |
| 12 | * The SCTP reference implementation is free software; |
| 13 | * you can redistribute it and/or modify it under the terms of |
| 14 | * the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2, or (at your option) |
| 16 | * any later version. |
| 17 | * |
| 18 | * The SCTP reference implementation is distributed in the hope that it |
| 19 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 20 | * ************************ |
| 21 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 22 | * See the GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with GNU CC; see the file COPYING. If not, write to |
| 26 | * the Free Software Foundation, 59 Temple Place - Suite 330, |
| 27 | * Boston, MA 02111-1307, USA. |
| 28 | * |
| 29 | * Please send any bug reports or fixes you make to the |
| 30 | * email address(es): |
| 31 | * lksctp developers <lksctp-developers@lists.sourceforge.net> |
| 32 | * |
| 33 | * Or submit a bug report through the following website: |
| 34 | * http://www.sf.net/projects/lksctp |
| 35 | * |
| 36 | * Written or modified by: |
| 37 | * La Monte H.P. Yarroll <piggy@acm.org> |
| 38 | * Karl Knutson <karl@athena.chicago.il.us> |
| 39 | * Perry Melange <pmelange@null.cc.uic.edu> |
| 40 | * Xingang Guo <xingang.guo@intel.com> |
| 41 | * Hui Huang <hui.huang@nokia.com> |
| 42 | * Sridhar Samudrala <sri@us.ibm.com> |
| 43 | * Jon Grimm <jgrimm@us.ibm.com> |
| 44 | * |
| 45 | * Any bugs reported given to us we will try to fix... any fixes shared will |
| 46 | * be incorporated into the next SCTP release. |
| 47 | */ |
| 48 | |
| 49 | #include <linux/types.h> |
| 50 | #include <linux/list.h> /* For struct list_head */ |
| 51 | #include <linux/socket.h> |
| 52 | #include <linux/ip.h> |
| 53 | #include <net/sock.h> /* For skb_set_owner_w */ |
| 54 | |
| 55 | #include <net/sctp/sctp.h> |
| 56 | #include <net/sctp/sm.h> |
| 57 | |
| 58 | /* Declare internal functions here. */ |
| 59 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); |
| 60 | static void sctp_check_transmitted(struct sctp_outq *q, |
| 61 | struct list_head *transmitted_queue, |
| 62 | struct sctp_transport *transport, |
| 63 | struct sctp_sackhdr *sack, |
| 64 | __u32 highest_new_tsn); |
| 65 | |
| 66 | static void sctp_mark_missing(struct sctp_outq *q, |
| 67 | struct list_head *transmitted_queue, |
| 68 | struct sctp_transport *transport, |
| 69 | __u32 highest_new_tsn, |
| 70 | int count_of_newacks); |
| 71 | |
| 72 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); |
| 73 | |
| 74 | /* Add data to the front of the queue. */ |
| 75 | static inline void sctp_outq_head_data(struct sctp_outq *q, |
| 76 | struct sctp_chunk *ch) |
| 77 | { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 78 | list_add(&ch->list, &q->out_chunk_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | q->out_qlen += ch->skb->len; |
| 80 | return; |
| 81 | } |
| 82 | |
| 83 | /* Take data from the front of the queue. */ |
| 84 | static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) |
| 85 | { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 86 | struct sctp_chunk *ch = NULL; |
| 87 | |
| 88 | if (!list_empty(&q->out_chunk_list)) { |
| 89 | struct list_head *entry = q->out_chunk_list.next; |
| 90 | |
| 91 | ch = list_entry(entry, struct sctp_chunk, list); |
| 92 | list_del_init(entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | q->out_qlen -= ch->skb->len; |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 94 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | return ch; |
| 96 | } |
| 97 | /* Add data chunk to the end of the queue. */ |
| 98 | static inline void sctp_outq_tail_data(struct sctp_outq *q, |
| 99 | struct sctp_chunk *ch) |
| 100 | { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 101 | list_add_tail(&ch->list, &q->out_chunk_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | q->out_qlen += ch->skb->len; |
| 103 | return; |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * SFR-CACC algorithm: |
| 108 | * D) If count_of_newacks is greater than or equal to 2 |
| 109 | * and t was not sent to the current primary then the |
| 110 | * sender MUST NOT increment missing report count for t. |
| 111 | */ |
| 112 | static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, |
| 113 | struct sctp_transport *transport, |
| 114 | int count_of_newacks) |
| 115 | { |
| 116 | if (count_of_newacks >=2 && transport != primary) |
| 117 | return 1; |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * SFR-CACC algorithm: |
| 123 | * F) If count_of_newacks is less than 2, let d be the |
| 124 | * destination to which t was sent. If cacc_saw_newack |
| 125 | * is 0 for destination d, then the sender MUST NOT |
| 126 | * increment missing report count for t. |
| 127 | */ |
| 128 | static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, |
| 129 | int count_of_newacks) |
| 130 | { |
| 131 | if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack) |
| 132 | return 1; |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | /* |
| 137 | * SFR-CACC algorithm: |
| 138 | * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD |
| 139 | * execute steps C, D, F. |
| 140 | * |
| 141 | * C has been implemented in sctp_outq_sack |
| 142 | */ |
| 143 | static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, |
| 144 | struct sctp_transport *transport, |
| 145 | int count_of_newacks) |
| 146 | { |
| 147 | if (!primary->cacc.cycling_changeover) { |
| 148 | if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks)) |
| 149 | return 1; |
| 150 | if (sctp_cacc_skip_3_1_f(transport, count_of_newacks)) |
| 151 | return 1; |
| 152 | return 0; |
| 153 | } |
| 154 | return 0; |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * SFR-CACC algorithm: |
| 159 | * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less |
| 160 | * than next_tsn_at_change of the current primary, then |
| 161 | * the sender MUST NOT increment missing report count |
| 162 | * for t. |
| 163 | */ |
| 164 | static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) |
| 165 | { |
| 166 | if (primary->cacc.cycling_changeover && |
| 167 | TSN_lt(tsn, primary->cacc.next_tsn_at_change)) |
| 168 | return 1; |
| 169 | return 0; |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * SFR-CACC algorithm: |
| 174 | * 3) If the missing report count for TSN t is to be |
| 175 | * incremented according to [RFC2960] and |
| 176 | * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, |
| 177 | * then the sender MUST futher execute steps 3.1 and |
| 178 | * 3.2 to determine if the missing report count for |
| 179 | * TSN t SHOULD NOT be incremented. |
| 180 | * |
| 181 | * 3.3) If 3.1 and 3.2 do not dictate that the missing |
| 182 | * report count for t should not be incremented, then |
| 183 | * the sender SOULD increment missing report count for |
| 184 | * t (according to [RFC2960] and [SCTP_STEWART_2002]). |
| 185 | */ |
| 186 | static inline int sctp_cacc_skip(struct sctp_transport *primary, |
| 187 | struct sctp_transport *transport, |
| 188 | int count_of_newacks, |
| 189 | __u32 tsn) |
| 190 | { |
| 191 | if (primary->cacc.changeover_active && |
| 192 | (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) |
| 193 | || sctp_cacc_skip_3_2(primary, tsn))) |
| 194 | return 1; |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | /* Initialize an existing sctp_outq. This does the boring stuff. |
| 199 | * You still need to define handlers if you really want to DO |
| 200 | * something with this structure... |
| 201 | */ |
| 202 | void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) |
| 203 | { |
| 204 | q->asoc = asoc; |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 205 | INIT_LIST_HEAD(&q->out_chunk_list); |
| 206 | INIT_LIST_HEAD(&q->control_chunk_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | INIT_LIST_HEAD(&q->retransmit); |
| 208 | INIT_LIST_HEAD(&q->sacked); |
| 209 | INIT_LIST_HEAD(&q->abandoned); |
| 210 | |
| 211 | q->outstanding_bytes = 0; |
| 212 | q->empty = 1; |
| 213 | q->cork = 0; |
| 214 | |
| 215 | q->malloced = 0; |
| 216 | q->out_qlen = 0; |
| 217 | } |
| 218 | |
| 219 | /* Free the outqueue structure and any related pending chunks. |
| 220 | */ |
| 221 | void sctp_outq_teardown(struct sctp_outq *q) |
| 222 | { |
| 223 | struct sctp_transport *transport; |
| 224 | struct list_head *lchunk, *pos, *temp; |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 225 | struct sctp_chunk *chunk, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | |
| 227 | /* Throw away unacknowledged chunks. */ |
| 228 | list_for_each(pos, &q->asoc->peer.transport_addr_list) { |
| 229 | transport = list_entry(pos, struct sctp_transport, transports); |
| 230 | while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) { |
| 231 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 232 | transmitted_list); |
| 233 | /* Mark as part of a failed message. */ |
| 234 | sctp_chunk_fail(chunk, q->error); |
| 235 | sctp_chunk_free(chunk); |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | /* Throw away chunks that have been gap ACKed. */ |
| 240 | list_for_each_safe(lchunk, temp, &q->sacked) { |
| 241 | list_del_init(lchunk); |
| 242 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 243 | transmitted_list); |
| 244 | sctp_chunk_fail(chunk, q->error); |
| 245 | sctp_chunk_free(chunk); |
| 246 | } |
| 247 | |
| 248 | /* Throw away any chunks in the retransmit queue. */ |
| 249 | list_for_each_safe(lchunk, temp, &q->retransmit) { |
| 250 | list_del_init(lchunk); |
| 251 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 252 | transmitted_list); |
| 253 | sctp_chunk_fail(chunk, q->error); |
| 254 | sctp_chunk_free(chunk); |
| 255 | } |
| 256 | |
| 257 | /* Throw away any chunks that are in the abandoned queue. */ |
| 258 | list_for_each_safe(lchunk, temp, &q->abandoned) { |
| 259 | list_del_init(lchunk); |
| 260 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 261 | transmitted_list); |
| 262 | sctp_chunk_fail(chunk, q->error); |
| 263 | sctp_chunk_free(chunk); |
| 264 | } |
| 265 | |
| 266 | /* Throw away any leftover data chunks. */ |
| 267 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
| 268 | |
| 269 | /* Mark as send failure. */ |
| 270 | sctp_chunk_fail(chunk, q->error); |
| 271 | sctp_chunk_free(chunk); |
| 272 | } |
| 273 | |
| 274 | q->error = 0; |
| 275 | |
| 276 | /* Throw away any leftover control chunks. */ |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 277 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
| 278 | list_del_init(&chunk->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | sctp_chunk_free(chunk); |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 280 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | } |
| 282 | |
| 283 | /* Free the outqueue structure and any related pending chunks. */ |
| 284 | void sctp_outq_free(struct sctp_outq *q) |
| 285 | { |
| 286 | /* Throw away leftover chunks. */ |
| 287 | sctp_outq_teardown(q); |
| 288 | |
| 289 | /* If we were kmalloc()'d, free the memory. */ |
| 290 | if (q->malloced) |
| 291 | kfree(q); |
| 292 | } |
| 293 | |
| 294 | /* Put a new chunk in an sctp_outq. */ |
| 295 | int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) |
| 296 | { |
| 297 | int error = 0; |
| 298 | |
| 299 | SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n", |
| 300 | q, chunk, chunk && chunk->chunk_hdr ? |
| 301 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) |
| 302 | : "Illegal Chunk"); |
| 303 | |
| 304 | /* If it is data, queue it up, otherwise, send it |
| 305 | * immediately. |
| 306 | */ |
| 307 | if (SCTP_CID_DATA == chunk->chunk_hdr->type) { |
| 308 | /* Is it OK to queue data chunks? */ |
| 309 | /* From 9. Termination of Association |
| 310 | * |
| 311 | * When either endpoint performs a shutdown, the |
| 312 | * association on each peer will stop accepting new |
| 313 | * data from its user and only deliver data in queue |
| 314 | * at the time of sending or receiving the SHUTDOWN |
| 315 | * chunk. |
| 316 | */ |
| 317 | switch (q->asoc->state) { |
| 318 | case SCTP_STATE_EMPTY: |
| 319 | case SCTP_STATE_CLOSED: |
| 320 | case SCTP_STATE_SHUTDOWN_PENDING: |
| 321 | case SCTP_STATE_SHUTDOWN_SENT: |
| 322 | case SCTP_STATE_SHUTDOWN_RECEIVED: |
| 323 | case SCTP_STATE_SHUTDOWN_ACK_SENT: |
| 324 | /* Cannot send after transport endpoint shutdown */ |
| 325 | error = -ESHUTDOWN; |
| 326 | break; |
| 327 | |
| 328 | default: |
| 329 | SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n", |
| 330 | q, chunk, chunk && chunk->chunk_hdr ? |
| 331 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) |
| 332 | : "Illegal Chunk"); |
| 333 | |
| 334 | sctp_outq_tail_data(q, chunk); |
| 335 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) |
| 336 | SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS); |
| 337 | else |
| 338 | SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS); |
| 339 | q->empty = 0; |
| 340 | break; |
| 341 | }; |
| 342 | } else { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 343 | list_add_tail(&chunk->list, &q->control_chunk_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 345 | } |
| 346 | |
| 347 | if (error < 0) |
| 348 | return error; |
| 349 | |
| 350 | if (!q->cork) |
| 351 | error = sctp_outq_flush(q, 0); |
| 352 | |
| 353 | return error; |
| 354 | } |
| 355 | |
| 356 | /* Insert a chunk into the sorted list based on the TSNs. The retransmit list |
| 357 | * and the abandoned list are in ascending order. |
| 358 | */ |
| 359 | static void sctp_insert_list(struct list_head *head, struct list_head *new) |
| 360 | { |
| 361 | struct list_head *pos; |
| 362 | struct sctp_chunk *nchunk, *lchunk; |
| 363 | __u32 ntsn, ltsn; |
| 364 | int done = 0; |
| 365 | |
| 366 | nchunk = list_entry(new, struct sctp_chunk, transmitted_list); |
| 367 | ntsn = ntohl(nchunk->subh.data_hdr->tsn); |
| 368 | |
| 369 | list_for_each(pos, head) { |
| 370 | lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); |
| 371 | ltsn = ntohl(lchunk->subh.data_hdr->tsn); |
| 372 | if (TSN_lt(ntsn, ltsn)) { |
| 373 | list_add(new, pos->prev); |
| 374 | done = 1; |
| 375 | break; |
| 376 | } |
| 377 | } |
| 378 | if (!done) |
| 379 | list_add_tail(new, head); |
| 380 | } |
| 381 | |
| 382 | /* Mark all the eligible packets on a transport for retransmission. */ |
| 383 | void sctp_retransmit_mark(struct sctp_outq *q, |
| 384 | struct sctp_transport *transport, |
| 385 | __u8 fast_retransmit) |
| 386 | { |
| 387 | struct list_head *lchunk, *ltemp; |
| 388 | struct sctp_chunk *chunk; |
| 389 | |
| 390 | /* Walk through the specified transmitted queue. */ |
| 391 | list_for_each_safe(lchunk, ltemp, &transport->transmitted) { |
| 392 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 393 | transmitted_list); |
| 394 | |
| 395 | /* If the chunk is abandoned, move it to abandoned list. */ |
| 396 | if (sctp_chunk_abandoned(chunk)) { |
| 397 | list_del_init(lchunk); |
| 398 | sctp_insert_list(&q->abandoned, lchunk); |
| 399 | continue; |
| 400 | } |
| 401 | |
| 402 | /* If we are doing retransmission due to a fast retransmit, |
| 403 | * only the chunk's that are marked for fast retransmit |
| 404 | * should be added to the retransmit queue. If we are doing |
| 405 | * retransmission due to a timeout or pmtu discovery, only the |
| 406 | * chunks that are not yet acked should be added to the |
| 407 | * retransmit queue. |
| 408 | */ |
Vlad Yasevich | 27852c2 | 2006-02-02 16:57:31 -0800 | [diff] [blame^] | 409 | if ((fast_retransmit && (chunk->fast_retransmit > 0)) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | (!fast_retransmit && !chunk->tsn_gap_acked)) { |
| 411 | /* RFC 2960 6.2.1 Processing a Received SACK |
| 412 | * |
| 413 | * C) Any time a DATA chunk is marked for |
| 414 | * retransmission (via either T3-rtx timer expiration |
| 415 | * (Section 6.3.3) or via fast retransmit |
| 416 | * (Section 7.2.4)), add the data size of those |
| 417 | * chunks to the rwnd. |
| 418 | */ |
| 419 | q->asoc->peer.rwnd += sctp_data_size(chunk); |
| 420 | q->outstanding_bytes -= sctp_data_size(chunk); |
| 421 | transport->flight_size -= sctp_data_size(chunk); |
| 422 | |
| 423 | /* sctpimpguide-05 Section 2.8.2 |
| 424 | * M5) If a T3-rtx timer expires, the |
| 425 | * 'TSN.Missing.Report' of all affected TSNs is set |
| 426 | * to 0. |
| 427 | */ |
| 428 | chunk->tsn_missing_report = 0; |
| 429 | |
| 430 | /* If a chunk that is being used for RTT measurement |
| 431 | * has to be retransmitted, we cannot use this chunk |
| 432 | * anymore for RTT measurements. Reset rto_pending so |
| 433 | * that a new RTT measurement is started when a new |
| 434 | * data chunk is sent. |
| 435 | */ |
| 436 | if (chunk->rtt_in_progress) { |
| 437 | chunk->rtt_in_progress = 0; |
| 438 | transport->rto_pending = 0; |
| 439 | } |
| 440 | |
| 441 | /* Move the chunk to the retransmit queue. The chunks |
| 442 | * on the retransmit queue are always kept in order. |
| 443 | */ |
| 444 | list_del_init(lchunk); |
| 445 | sctp_insert_list(&q->retransmit, lchunk); |
| 446 | } |
| 447 | } |
| 448 | |
| 449 | SCTP_DEBUG_PRINTK("%s: transport: %p, fast_retransmit: %d, " |
| 450 | "cwnd: %d, ssthresh: %d, flight_size: %d, " |
| 451 | "pba: %d\n", __FUNCTION__, |
| 452 | transport, fast_retransmit, |
| 453 | transport->cwnd, transport->ssthresh, |
| 454 | transport->flight_size, |
| 455 | transport->partial_bytes_acked); |
| 456 | |
| 457 | } |
| 458 | |
| 459 | /* Mark all the eligible packets on a transport for retransmission and force |
| 460 | * one packet out. |
| 461 | */ |
| 462 | void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, |
| 463 | sctp_retransmit_reason_t reason) |
| 464 | { |
| 465 | int error = 0; |
| 466 | __u8 fast_retransmit = 0; |
| 467 | |
| 468 | switch(reason) { |
| 469 | case SCTP_RTXR_T3_RTX: |
| 470 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); |
| 471 | /* Update the retran path if the T3-rtx timer has expired for |
| 472 | * the current retran path. |
| 473 | */ |
| 474 | if (transport == transport->asoc->peer.retran_path) |
| 475 | sctp_assoc_update_retran_path(transport->asoc); |
| 476 | break; |
| 477 | case SCTP_RTXR_FAST_RTX: |
| 478 | sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); |
| 479 | fast_retransmit = 1; |
| 480 | break; |
| 481 | case SCTP_RTXR_PMTUD: |
| 482 | default: |
| 483 | break; |
| 484 | } |
| 485 | |
| 486 | sctp_retransmit_mark(q, transport, fast_retransmit); |
| 487 | |
| 488 | /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, |
| 489 | * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by |
| 490 | * following the procedures outlined in C1 - C5. |
| 491 | */ |
| 492 | sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); |
| 493 | |
| 494 | error = sctp_outq_flush(q, /* rtx_timeout */ 1); |
| 495 | |
| 496 | if (error) |
| 497 | q->asoc->base.sk->sk_err = -error; |
| 498 | } |
| 499 | |
| 500 | /* |
| 501 | * Transmit DATA chunks on the retransmit queue. Upon return from |
| 502 | * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which |
| 503 | * need to be transmitted by the caller. |
| 504 | * We assume that pkt->transport has already been set. |
| 505 | * |
| 506 | * The return value is a normal kernel error return value. |
| 507 | */ |
| 508 | static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, |
| 509 | int rtx_timeout, int *start_timer) |
| 510 | { |
| 511 | struct list_head *lqueue; |
| 512 | struct list_head *lchunk, *lchunk1; |
| 513 | struct sctp_transport *transport = pkt->transport; |
| 514 | sctp_xmit_t status; |
| 515 | struct sctp_chunk *chunk, *chunk1; |
| 516 | struct sctp_association *asoc; |
| 517 | int error = 0; |
| 518 | |
| 519 | asoc = q->asoc; |
| 520 | lqueue = &q->retransmit; |
| 521 | |
| 522 | /* RFC 2960 6.3.3 Handle T3-rtx Expiration |
| 523 | * |
| 524 | * E3) Determine how many of the earliest (i.e., lowest TSN) |
| 525 | * outstanding DATA chunks for the address for which the |
| 526 | * T3-rtx has expired will fit into a single packet, subject |
| 527 | * to the MTU constraint for the path corresponding to the |
| 528 | * destination transport address to which the retransmission |
| 529 | * is being sent (this may be different from the address for |
| 530 | * which the timer expires [see Section 6.4]). Call this value |
| 531 | * K. Bundle and retransmit those K DATA chunks in a single |
| 532 | * packet to the destination endpoint. |
| 533 | * |
| 534 | * [Just to be painfully clear, if we are retransmitting |
| 535 | * because a timeout just happened, we should send only ONE |
| 536 | * packet of retransmitted data.] |
| 537 | */ |
| 538 | lchunk = sctp_list_dequeue(lqueue); |
| 539 | |
| 540 | while (lchunk) { |
| 541 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 542 | transmitted_list); |
| 543 | |
| 544 | /* Make sure that Gap Acked TSNs are not retransmitted. A |
| 545 | * simple approach is just to move such TSNs out of the |
| 546 | * way and into a 'transmitted' queue and skip to the |
| 547 | * next chunk. |
| 548 | */ |
| 549 | if (chunk->tsn_gap_acked) { |
| 550 | list_add_tail(lchunk, &transport->transmitted); |
| 551 | lchunk = sctp_list_dequeue(lqueue); |
| 552 | continue; |
| 553 | } |
| 554 | |
| 555 | /* Attempt to append this chunk to the packet. */ |
| 556 | status = sctp_packet_append_chunk(pkt, chunk); |
| 557 | |
| 558 | switch (status) { |
| 559 | case SCTP_XMIT_PMTU_FULL: |
| 560 | /* Send this packet. */ |
| 561 | if ((error = sctp_packet_transmit(pkt)) == 0) |
| 562 | *start_timer = 1; |
| 563 | |
| 564 | /* If we are retransmitting, we should only |
| 565 | * send a single packet. |
| 566 | */ |
| 567 | if (rtx_timeout) { |
| 568 | list_add(lchunk, lqueue); |
| 569 | lchunk = NULL; |
| 570 | } |
| 571 | |
| 572 | /* Bundle lchunk in the next round. */ |
| 573 | break; |
| 574 | |
| 575 | case SCTP_XMIT_RWND_FULL: |
| 576 | /* Send this packet. */ |
| 577 | if ((error = sctp_packet_transmit(pkt)) == 0) |
| 578 | *start_timer = 1; |
| 579 | |
| 580 | /* Stop sending DATA as there is no more room |
| 581 | * at the receiver. |
| 582 | */ |
| 583 | list_add(lchunk, lqueue); |
| 584 | lchunk = NULL; |
| 585 | break; |
| 586 | |
| 587 | case SCTP_XMIT_NAGLE_DELAY: |
| 588 | /* Send this packet. */ |
| 589 | if ((error = sctp_packet_transmit(pkt)) == 0) |
| 590 | *start_timer = 1; |
| 591 | |
| 592 | /* Stop sending DATA because of nagle delay. */ |
| 593 | list_add(lchunk, lqueue); |
| 594 | lchunk = NULL; |
| 595 | break; |
| 596 | |
| 597 | default: |
| 598 | /* The append was successful, so add this chunk to |
| 599 | * the transmitted list. |
| 600 | */ |
| 601 | list_add_tail(lchunk, &transport->transmitted); |
| 602 | |
| 603 | /* Mark the chunk as ineligible for fast retransmit |
| 604 | * after it is retransmitted. |
| 605 | */ |
Vlad Yasevich | 27852c2 | 2006-02-02 16:57:31 -0800 | [diff] [blame^] | 606 | if (chunk->fast_retransmit > 0) |
| 607 | chunk->fast_retransmit = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | |
| 609 | *start_timer = 1; |
| 610 | q->empty = 0; |
| 611 | |
| 612 | /* Retrieve a new chunk to bundle. */ |
| 613 | lchunk = sctp_list_dequeue(lqueue); |
| 614 | break; |
| 615 | }; |
| 616 | |
| 617 | /* If we are here due to a retransmit timeout or a fast |
| 618 | * retransmit and if there are any chunks left in the retransmit |
| 619 | * queue that could not fit in the PMTU sized packet, they need * to be marked as ineligible for a subsequent fast retransmit. |
| 620 | */ |
| 621 | if (rtx_timeout && !lchunk) { |
| 622 | list_for_each(lchunk1, lqueue) { |
| 623 | chunk1 = list_entry(lchunk1, struct sctp_chunk, |
| 624 | transmitted_list); |
Vlad Yasevich | 27852c2 | 2006-02-02 16:57:31 -0800 | [diff] [blame^] | 625 | if (chunk1->fast_retransmit > 0) |
| 626 | chunk1->fast_retransmit = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | } |
| 628 | } |
| 629 | } |
| 630 | |
| 631 | return error; |
| 632 | } |
| 633 | |
| 634 | /* Cork the outqueue so queued chunks are really queued. */ |
| 635 | int sctp_outq_uncork(struct sctp_outq *q) |
| 636 | { |
| 637 | int error = 0; |
| 638 | if (q->cork) { |
| 639 | q->cork = 0; |
| 640 | error = sctp_outq_flush(q, 0); |
| 641 | } |
| 642 | return error; |
| 643 | } |
| 644 | |
| 645 | /* |
| 646 | * Try to flush an outqueue. |
| 647 | * |
| 648 | * Description: Send everything in q which we legally can, subject to |
| 649 | * congestion limitations. |
| 650 | * * Note: This function can be called from multiple contexts so appropriate |
| 651 | * locking concerns must be made. Today we use the sock lock to protect |
| 652 | * this function. |
| 653 | */ |
| 654 | int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) |
| 655 | { |
| 656 | struct sctp_packet *packet; |
| 657 | struct sctp_packet singleton; |
| 658 | struct sctp_association *asoc = q->asoc; |
| 659 | __u16 sport = asoc->base.bind_addr.port; |
| 660 | __u16 dport = asoc->peer.port; |
| 661 | __u32 vtag = asoc->peer.i.init_tag; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | struct sctp_transport *transport = NULL; |
| 663 | struct sctp_transport *new_transport; |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 664 | struct sctp_chunk *chunk, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | sctp_xmit_t status; |
| 666 | int error = 0; |
| 667 | int start_timer = 0; |
| 668 | |
| 669 | /* These transports have chunks to send. */ |
| 670 | struct list_head transport_list; |
| 671 | struct list_head *ltransport; |
| 672 | |
| 673 | INIT_LIST_HEAD(&transport_list); |
| 674 | packet = NULL; |
| 675 | |
| 676 | /* |
| 677 | * 6.10 Bundling |
| 678 | * ... |
| 679 | * When bundling control chunks with DATA chunks, an |
| 680 | * endpoint MUST place control chunks first in the outbound |
| 681 | * SCTP packet. The transmitter MUST transmit DATA chunks |
| 682 | * within a SCTP packet in increasing order of TSN. |
| 683 | * ... |
| 684 | */ |
| 685 | |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 686 | list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) { |
| 687 | list_del_init(&chunk->list); |
| 688 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | /* Pick the right transport to use. */ |
| 690 | new_transport = chunk->transport; |
| 691 | |
| 692 | if (!new_transport) { |
| 693 | new_transport = asoc->peer.active_path; |
Frank Filz | 3f7a87d | 2005-06-20 13:14:57 -0700 | [diff] [blame] | 694 | } else if (new_transport->state == SCTP_INACTIVE) { |
| 695 | /* If the chunk is Heartbeat or Heartbeat Ack, |
| 696 | * send it to chunk->transport, even if it's |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | * inactive. |
| 698 | * |
| 699 | * 3.3.6 Heartbeat Acknowledgement: |
| 700 | * ... |
| 701 | * A HEARTBEAT ACK is always sent to the source IP |
| 702 | * address of the IP datagram containing the |
| 703 | * HEARTBEAT chunk to which this ack is responding. |
| 704 | * ... |
| 705 | */ |
| 706 | if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && |
| 707 | chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK) |
| 708 | new_transport = asoc->peer.active_path; |
| 709 | } |
| 710 | |
| 711 | /* Are we switching transports? |
| 712 | * Take care of transport locks. |
| 713 | */ |
| 714 | if (new_transport != transport) { |
| 715 | transport = new_transport; |
| 716 | if (list_empty(&transport->send_ready)) { |
| 717 | list_add_tail(&transport->send_ready, |
| 718 | &transport_list); |
| 719 | } |
| 720 | packet = &transport->packet; |
| 721 | sctp_packet_config(packet, vtag, |
| 722 | asoc->peer.ecn_capable); |
| 723 | } |
| 724 | |
| 725 | switch (chunk->chunk_hdr->type) { |
| 726 | /* |
| 727 | * 6.10 Bundling |
| 728 | * ... |
| 729 | * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN |
| 730 | * COMPLETE with any other chunks. [Send them immediately.] |
| 731 | */ |
| 732 | case SCTP_CID_INIT: |
| 733 | case SCTP_CID_INIT_ACK: |
| 734 | case SCTP_CID_SHUTDOWN_COMPLETE: |
| 735 | sctp_packet_init(&singleton, transport, sport, dport); |
| 736 | sctp_packet_config(&singleton, vtag, 0); |
| 737 | sctp_packet_append_chunk(&singleton, chunk); |
| 738 | error = sctp_packet_transmit(&singleton); |
| 739 | if (error < 0) |
| 740 | return error; |
| 741 | break; |
| 742 | |
| 743 | case SCTP_CID_ABORT: |
| 744 | case SCTP_CID_SACK: |
| 745 | case SCTP_CID_HEARTBEAT: |
| 746 | case SCTP_CID_HEARTBEAT_ACK: |
| 747 | case SCTP_CID_SHUTDOWN: |
| 748 | case SCTP_CID_SHUTDOWN_ACK: |
| 749 | case SCTP_CID_ERROR: |
| 750 | case SCTP_CID_COOKIE_ECHO: |
| 751 | case SCTP_CID_COOKIE_ACK: |
| 752 | case SCTP_CID_ECN_ECNE: |
| 753 | case SCTP_CID_ECN_CWR: |
| 754 | case SCTP_CID_ASCONF: |
| 755 | case SCTP_CID_ASCONF_ACK: |
| 756 | case SCTP_CID_FWD_TSN: |
| 757 | sctp_packet_transmit_chunk(packet, chunk); |
| 758 | break; |
| 759 | |
| 760 | default: |
| 761 | /* We built a chunk with an illegal type! */ |
| 762 | BUG(); |
| 763 | }; |
| 764 | } |
| 765 | |
| 766 | /* Is it OK to send data chunks? */ |
| 767 | switch (asoc->state) { |
| 768 | case SCTP_STATE_COOKIE_ECHOED: |
| 769 | /* Only allow bundling when this packet has a COOKIE-ECHO |
| 770 | * chunk. |
| 771 | */ |
| 772 | if (!packet || !packet->has_cookie_echo) |
| 773 | break; |
| 774 | |
| 775 | /* fallthru */ |
| 776 | case SCTP_STATE_ESTABLISHED: |
| 777 | case SCTP_STATE_SHUTDOWN_PENDING: |
| 778 | case SCTP_STATE_SHUTDOWN_RECEIVED: |
| 779 | /* |
| 780 | * RFC 2960 6.1 Transmission of DATA Chunks |
| 781 | * |
| 782 | * C) When the time comes for the sender to transmit, |
| 783 | * before sending new DATA chunks, the sender MUST |
| 784 | * first transmit any outstanding DATA chunks which |
| 785 | * are marked for retransmission (limited by the |
| 786 | * current cwnd). |
| 787 | */ |
| 788 | if (!list_empty(&q->retransmit)) { |
| 789 | if (transport == asoc->peer.retran_path) |
| 790 | goto retran; |
| 791 | |
| 792 | /* Switch transports & prepare the packet. */ |
| 793 | |
| 794 | transport = asoc->peer.retran_path; |
| 795 | |
| 796 | if (list_empty(&transport->send_ready)) { |
| 797 | list_add_tail(&transport->send_ready, |
| 798 | &transport_list); |
| 799 | } |
| 800 | |
| 801 | packet = &transport->packet; |
| 802 | sctp_packet_config(packet, vtag, |
| 803 | asoc->peer.ecn_capable); |
| 804 | retran: |
| 805 | error = sctp_outq_flush_rtx(q, packet, |
| 806 | rtx_timeout, &start_timer); |
| 807 | |
| 808 | if (start_timer) |
| 809 | sctp_transport_reset_timers(transport); |
| 810 | |
| 811 | /* This can happen on COOKIE-ECHO resend. Only |
| 812 | * one chunk can get bundled with a COOKIE-ECHO. |
| 813 | */ |
| 814 | if (packet->has_cookie_echo) |
| 815 | goto sctp_flush_out; |
| 816 | |
| 817 | /* Don't send new data if there is still data |
| 818 | * waiting to retransmit. |
| 819 | */ |
| 820 | if (!list_empty(&q->retransmit)) |
| 821 | goto sctp_flush_out; |
| 822 | } |
| 823 | |
| 824 | /* Finally, transmit new packets. */ |
| 825 | start_timer = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { |
| 827 | /* RFC 2960 6.5 Every DATA chunk MUST carry a valid |
| 828 | * stream identifier. |
| 829 | */ |
| 830 | if (chunk->sinfo.sinfo_stream >= |
| 831 | asoc->c.sinit_num_ostreams) { |
| 832 | |
| 833 | /* Mark as failed send. */ |
| 834 | sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); |
| 835 | sctp_chunk_free(chunk); |
| 836 | continue; |
| 837 | } |
| 838 | |
| 839 | /* Has this chunk expired? */ |
| 840 | if (sctp_chunk_abandoned(chunk)) { |
| 841 | sctp_chunk_fail(chunk, 0); |
| 842 | sctp_chunk_free(chunk); |
| 843 | continue; |
| 844 | } |
| 845 | |
| 846 | /* If there is a specified transport, use it. |
| 847 | * Otherwise, we want to use the active path. |
| 848 | */ |
| 849 | new_transport = chunk->transport; |
Frank Filz | 3f7a87d | 2005-06-20 13:14:57 -0700 | [diff] [blame] | 850 | if (!new_transport || |
| 851 | new_transport->state == SCTP_INACTIVE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | new_transport = asoc->peer.active_path; |
| 853 | |
| 854 | /* Change packets if necessary. */ |
| 855 | if (new_transport != transport) { |
| 856 | transport = new_transport; |
| 857 | |
| 858 | /* Schedule to have this transport's |
| 859 | * packet flushed. |
| 860 | */ |
| 861 | if (list_empty(&transport->send_ready)) { |
| 862 | list_add_tail(&transport->send_ready, |
| 863 | &transport_list); |
| 864 | } |
| 865 | |
| 866 | packet = &transport->packet; |
| 867 | sctp_packet_config(packet, vtag, |
| 868 | asoc->peer.ecn_capable); |
| 869 | } |
| 870 | |
| 871 | SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ", |
| 872 | q, chunk, |
| 873 | chunk && chunk->chunk_hdr ? |
| 874 | sctp_cname(SCTP_ST_CHUNK( |
| 875 | chunk->chunk_hdr->type)) |
| 876 | : "Illegal Chunk"); |
| 877 | |
| 878 | SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head " |
| 879 | "%p skb->users %d.\n", |
| 880 | ntohl(chunk->subh.data_hdr->tsn), |
| 881 | chunk->skb ?chunk->skb->head : NULL, |
| 882 | chunk->skb ? |
| 883 | atomic_read(&chunk->skb->users) : -1); |
| 884 | |
| 885 | /* Add the chunk to the packet. */ |
| 886 | status = sctp_packet_transmit_chunk(packet, chunk); |
| 887 | |
| 888 | switch (status) { |
| 889 | case SCTP_XMIT_PMTU_FULL: |
| 890 | case SCTP_XMIT_RWND_FULL: |
| 891 | case SCTP_XMIT_NAGLE_DELAY: |
| 892 | /* We could not append this chunk, so put |
| 893 | * the chunk back on the output queue. |
| 894 | */ |
| 895 | SCTP_DEBUG_PRINTK("sctp_outq_flush: could " |
| 896 | "not transmit TSN: 0x%x, status: %d\n", |
| 897 | ntohl(chunk->subh.data_hdr->tsn), |
| 898 | status); |
| 899 | sctp_outq_head_data(q, chunk); |
| 900 | goto sctp_flush_out; |
| 901 | break; |
| 902 | |
| 903 | case SCTP_XMIT_OK: |
| 904 | break; |
| 905 | |
| 906 | default: |
| 907 | BUG(); |
| 908 | } |
| 909 | |
| 910 | /* BUG: We assume that the sctp_packet_transmit() |
| 911 | * call below will succeed all the time and add the |
| 912 | * chunk to the transmitted list and restart the |
| 913 | * timers. |
| 914 | * It is possible that the call can fail under OOM |
| 915 | * conditions. |
| 916 | * |
| 917 | * Is this really a problem? Won't this behave |
| 918 | * like a lost TSN? |
| 919 | */ |
| 920 | list_add_tail(&chunk->transmitted_list, |
| 921 | &transport->transmitted); |
| 922 | |
| 923 | sctp_transport_reset_timers(transport); |
| 924 | |
| 925 | q->empty = 0; |
| 926 | |
| 927 | /* Only let one DATA chunk get bundled with a |
| 928 | * COOKIE-ECHO chunk. |
| 929 | */ |
| 930 | if (packet->has_cookie_echo) |
| 931 | goto sctp_flush_out; |
| 932 | } |
| 933 | break; |
| 934 | |
| 935 | default: |
| 936 | /* Do nothing. */ |
| 937 | break; |
| 938 | } |
| 939 | |
| 940 | sctp_flush_out: |
| 941 | |
| 942 | /* Before returning, examine all the transports touched in |
| 943 | * this call. Right now, we bluntly force clear all the |
| 944 | * transports. Things might change after we implement Nagle. |
| 945 | * But such an examination is still required. |
| 946 | * |
| 947 | * --xguo |
| 948 | */ |
| 949 | while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) { |
| 950 | struct sctp_transport *t = list_entry(ltransport, |
| 951 | struct sctp_transport, |
| 952 | send_ready); |
| 953 | packet = &t->packet; |
| 954 | if (!sctp_packet_empty(packet)) |
| 955 | error = sctp_packet_transmit(packet); |
| 956 | } |
| 957 | |
| 958 | return error; |
| 959 | } |
| 960 | |
| 961 | /* Update unack_data based on the incoming SACK chunk */ |
| 962 | static void sctp_sack_update_unack_data(struct sctp_association *assoc, |
| 963 | struct sctp_sackhdr *sack) |
| 964 | { |
| 965 | sctp_sack_variable_t *frags; |
| 966 | __u16 unack_data; |
| 967 | int i; |
| 968 | |
| 969 | unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; |
| 970 | |
| 971 | frags = sack->variable; |
| 972 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { |
| 973 | unack_data -= ((ntohs(frags[i].gab.end) - |
| 974 | ntohs(frags[i].gab.start) + 1)); |
| 975 | } |
| 976 | |
| 977 | assoc->unack_data = unack_data; |
| 978 | } |
| 979 | |
| 980 | /* Return the highest new tsn that is acknowledged by the given SACK chunk. */ |
| 981 | static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack, |
| 982 | struct sctp_association *asoc) |
| 983 | { |
| 984 | struct list_head *ltransport, *lchunk; |
| 985 | struct sctp_transport *transport; |
| 986 | struct sctp_chunk *chunk; |
| 987 | __u32 highest_new_tsn, tsn; |
| 988 | struct list_head *transport_list = &asoc->peer.transport_addr_list; |
| 989 | |
| 990 | highest_new_tsn = ntohl(sack->cum_tsn_ack); |
| 991 | |
| 992 | list_for_each(ltransport, transport_list) { |
| 993 | transport = list_entry(ltransport, struct sctp_transport, |
| 994 | transports); |
| 995 | list_for_each(lchunk, &transport->transmitted) { |
| 996 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 997 | transmitted_list); |
| 998 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
| 999 | |
| 1000 | if (!chunk->tsn_gap_acked && |
| 1001 | TSN_lt(highest_new_tsn, tsn) && |
| 1002 | sctp_acked(sack, tsn)) |
| 1003 | highest_new_tsn = tsn; |
| 1004 | } |
| 1005 | } |
| 1006 | |
| 1007 | return highest_new_tsn; |
| 1008 | } |
| 1009 | |
| 1010 | /* This is where we REALLY process a SACK. |
| 1011 | * |
| 1012 | * Process the SACK against the outqueue. Mostly, this just frees |
| 1013 | * things off the transmitted queue. |
| 1014 | */ |
| 1015 | int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) |
| 1016 | { |
| 1017 | struct sctp_association *asoc = q->asoc; |
| 1018 | struct sctp_transport *transport; |
| 1019 | struct sctp_chunk *tchunk = NULL; |
| 1020 | struct list_head *lchunk, *transport_list, *pos, *temp; |
| 1021 | sctp_sack_variable_t *frags = sack->variable; |
| 1022 | __u32 sack_ctsn, ctsn, tsn; |
| 1023 | __u32 highest_tsn, highest_new_tsn; |
| 1024 | __u32 sack_a_rwnd; |
| 1025 | unsigned outstanding; |
| 1026 | struct sctp_transport *primary = asoc->peer.primary_path; |
| 1027 | int count_of_newacks = 0; |
| 1028 | |
| 1029 | /* Grab the association's destination address list. */ |
| 1030 | transport_list = &asoc->peer.transport_addr_list; |
| 1031 | |
| 1032 | sack_ctsn = ntohl(sack->cum_tsn_ack); |
| 1033 | |
| 1034 | /* |
| 1035 | * SFR-CACC algorithm: |
| 1036 | * On receipt of a SACK the sender SHOULD execute the |
| 1037 | * following statements. |
| 1038 | * |
| 1039 | * 1) If the cumulative ack in the SACK passes next tsn_at_change |
| 1040 | * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be |
| 1041 | * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for |
| 1042 | * all destinations. |
| 1043 | */ |
| 1044 | if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { |
| 1045 | primary->cacc.changeover_active = 0; |
| 1046 | list_for_each(pos, transport_list) { |
| 1047 | transport = list_entry(pos, struct sctp_transport, |
| 1048 | transports); |
| 1049 | transport->cacc.cycling_changeover = 0; |
| 1050 | } |
| 1051 | } |
| 1052 | |
| 1053 | /* |
| 1054 | * SFR-CACC algorithm: |
| 1055 | * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE |
| 1056 | * is set the receiver of the SACK MUST take the following actions: |
| 1057 | * |
| 1058 | * A) Initialize the cacc_saw_newack to 0 for all destination |
| 1059 | * addresses. |
| 1060 | */ |
| 1061 | if (sack->num_gap_ack_blocks > 0 && |
| 1062 | primary->cacc.changeover_active) { |
| 1063 | list_for_each(pos, transport_list) { |
| 1064 | transport = list_entry(pos, struct sctp_transport, |
| 1065 | transports); |
| 1066 | transport->cacc.cacc_saw_newack = 0; |
| 1067 | } |
| 1068 | } |
| 1069 | |
| 1070 | /* Get the highest TSN in the sack. */ |
| 1071 | highest_tsn = sack_ctsn; |
| 1072 | if (sack->num_gap_ack_blocks) |
| 1073 | highest_tsn += |
| 1074 | ntohs(frags[ntohs(sack->num_gap_ack_blocks) - 1].gab.end); |
| 1075 | |
| 1076 | if (TSN_lt(asoc->highest_sacked, highest_tsn)) { |
| 1077 | highest_new_tsn = highest_tsn; |
| 1078 | asoc->highest_sacked = highest_tsn; |
| 1079 | } else { |
| 1080 | highest_new_tsn = sctp_highest_new_tsn(sack, asoc); |
| 1081 | } |
| 1082 | |
| 1083 | /* Run through the retransmit queue. Credit bytes received |
| 1084 | * and free those chunks that we can. |
| 1085 | */ |
| 1086 | sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn); |
| 1087 | sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0); |
| 1088 | |
| 1089 | /* Run through the transmitted queue. |
| 1090 | * Credit bytes received and free those chunks which we can. |
| 1091 | * |
| 1092 | * This is a MASSIVE candidate for optimization. |
| 1093 | */ |
| 1094 | list_for_each(pos, transport_list) { |
| 1095 | transport = list_entry(pos, struct sctp_transport, |
| 1096 | transports); |
| 1097 | sctp_check_transmitted(q, &transport->transmitted, |
| 1098 | transport, sack, highest_new_tsn); |
| 1099 | /* |
| 1100 | * SFR-CACC algorithm: |
| 1101 | * C) Let count_of_newacks be the number of |
| 1102 | * destinations for which cacc_saw_newack is set. |
| 1103 | */ |
| 1104 | if (transport->cacc.cacc_saw_newack) |
| 1105 | count_of_newacks ++; |
| 1106 | } |
| 1107 | |
| 1108 | list_for_each(pos, transport_list) { |
| 1109 | transport = list_entry(pos, struct sctp_transport, |
| 1110 | transports); |
| 1111 | sctp_mark_missing(q, &transport->transmitted, transport, |
| 1112 | highest_new_tsn, count_of_newacks); |
| 1113 | } |
| 1114 | |
| 1115 | /* Move the Cumulative TSN Ack Point if appropriate. */ |
| 1116 | if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) |
| 1117 | asoc->ctsn_ack_point = sack_ctsn; |
| 1118 | |
| 1119 | /* Update unack_data field in the assoc. */ |
| 1120 | sctp_sack_update_unack_data(asoc, sack); |
| 1121 | |
| 1122 | ctsn = asoc->ctsn_ack_point; |
| 1123 | |
| 1124 | /* Throw away stuff rotting on the sack queue. */ |
| 1125 | list_for_each_safe(lchunk, temp, &q->sacked) { |
| 1126 | tchunk = list_entry(lchunk, struct sctp_chunk, |
| 1127 | transmitted_list); |
| 1128 | tsn = ntohl(tchunk->subh.data_hdr->tsn); |
| 1129 | if (TSN_lte(tsn, ctsn)) |
| 1130 | sctp_chunk_free(tchunk); |
| 1131 | } |
| 1132 | |
| 1133 | /* ii) Set rwnd equal to the newly received a_rwnd minus the |
| 1134 | * number of bytes still outstanding after processing the |
| 1135 | * Cumulative TSN Ack and the Gap Ack Blocks. |
| 1136 | */ |
| 1137 | |
| 1138 | sack_a_rwnd = ntohl(sack->a_rwnd); |
| 1139 | outstanding = q->outstanding_bytes; |
| 1140 | |
| 1141 | if (outstanding < sack_a_rwnd) |
| 1142 | sack_a_rwnd -= outstanding; |
| 1143 | else |
| 1144 | sack_a_rwnd = 0; |
| 1145 | |
| 1146 | asoc->peer.rwnd = sack_a_rwnd; |
| 1147 | |
| 1148 | sctp_generate_fwdtsn(q, sack_ctsn); |
| 1149 | |
| 1150 | SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n", |
| 1151 | __FUNCTION__, sack_ctsn); |
| 1152 | SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, " |
| 1153 | "%p is 0x%x. Adv peer ack point: 0x%x\n", |
| 1154 | __FUNCTION__, asoc, ctsn, asoc->adv_peer_ack_point); |
| 1155 | |
| 1156 | /* See if all chunks are acked. |
| 1157 | * Make sure the empty queue handler will get run later. |
| 1158 | */ |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 1159 | q->empty = (list_empty(&q->out_chunk_list) && |
| 1160 | list_empty(&q->control_chunk_list) && |
| 1161 | list_empty(&q->retransmit)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | if (!q->empty) |
| 1163 | goto finish; |
| 1164 | |
| 1165 | list_for_each(pos, transport_list) { |
| 1166 | transport = list_entry(pos, struct sctp_transport, |
| 1167 | transports); |
| 1168 | q->empty = q->empty && list_empty(&transport->transmitted); |
| 1169 | if (!q->empty) |
| 1170 | goto finish; |
| 1171 | } |
| 1172 | |
| 1173 | SCTP_DEBUG_PRINTK("sack queue is empty.\n"); |
| 1174 | finish: |
| 1175 | return q->empty; |
| 1176 | } |
| 1177 | |
| 1178 | /* Is the outqueue empty? */ |
| 1179 | int sctp_outq_is_empty(const struct sctp_outq *q) |
| 1180 | { |
| 1181 | return q->empty; |
| 1182 | } |
| 1183 | |
| 1184 | /******************************************************************** |
| 1185 | * 2nd Level Abstractions |
| 1186 | ********************************************************************/ |
| 1187 | |
| 1188 | /* Go through a transport's transmitted list or the association's retransmit |
| 1189 | * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. |
| 1190 | * The retransmit list will not have an associated transport. |
| 1191 | * |
| 1192 | * I added coherent debug information output. --xguo |
| 1193 | * |
| 1194 | * Instead of printing 'sacked' or 'kept' for each TSN on the |
| 1195 | * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. |
| 1196 | * KEPT TSN6-TSN7, etc. |
| 1197 | */ |
| 1198 | static void sctp_check_transmitted(struct sctp_outq *q, |
| 1199 | struct list_head *transmitted_queue, |
| 1200 | struct sctp_transport *transport, |
| 1201 | struct sctp_sackhdr *sack, |
| 1202 | __u32 highest_new_tsn_in_sack) |
| 1203 | { |
| 1204 | struct list_head *lchunk; |
| 1205 | struct sctp_chunk *tchunk; |
| 1206 | struct list_head tlist; |
| 1207 | __u32 tsn; |
| 1208 | __u32 sack_ctsn; |
| 1209 | __u32 rtt; |
| 1210 | __u8 restart_timer = 0; |
| 1211 | int bytes_acked = 0; |
| 1212 | |
| 1213 | /* These state variables are for coherent debug output. --xguo */ |
| 1214 | |
| 1215 | #if SCTP_DEBUG |
| 1216 | __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */ |
| 1217 | __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */ |
| 1218 | __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */ |
| 1219 | __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */ |
| 1220 | |
| 1221 | /* 0 : The last TSN was ACKed. |
| 1222 | * 1 : The last TSN was NOT ACKed (i.e. KEPT). |
| 1223 | * -1: We need to initialize. |
| 1224 | */ |
| 1225 | int dbg_prt_state = -1; |
| 1226 | #endif /* SCTP_DEBUG */ |
| 1227 | |
| 1228 | sack_ctsn = ntohl(sack->cum_tsn_ack); |
| 1229 | |
| 1230 | INIT_LIST_HEAD(&tlist); |
| 1231 | |
| 1232 | /* The while loop will skip empty transmitted queues. */ |
| 1233 | while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) { |
| 1234 | tchunk = list_entry(lchunk, struct sctp_chunk, |
| 1235 | transmitted_list); |
| 1236 | |
| 1237 | if (sctp_chunk_abandoned(tchunk)) { |
| 1238 | /* Move the chunk to abandoned list. */ |
| 1239 | sctp_insert_list(&q->abandoned, lchunk); |
| 1240 | continue; |
| 1241 | } |
| 1242 | |
| 1243 | tsn = ntohl(tchunk->subh.data_hdr->tsn); |
| 1244 | if (sctp_acked(sack, tsn)) { |
| 1245 | /* If this queue is the retransmit queue, the |
| 1246 | * retransmit timer has already reclaimed |
| 1247 | * the outstanding bytes for this chunk, so only |
| 1248 | * count bytes associated with a transport. |
| 1249 | */ |
| 1250 | if (transport) { |
| 1251 | /* If this chunk is being used for RTT |
| 1252 | * measurement, calculate the RTT and update |
| 1253 | * the RTO using this value. |
| 1254 | * |
| 1255 | * 6.3.1 C5) Karn's algorithm: RTT measurements |
| 1256 | * MUST NOT be made using packets that were |
| 1257 | * retransmitted (and thus for which it is |
| 1258 | * ambiguous whether the reply was for the |
| 1259 | * first instance of the packet or a later |
| 1260 | * instance). |
| 1261 | */ |
| 1262 | if (!tchunk->tsn_gap_acked && |
| 1263 | !tchunk->resent && |
| 1264 | tchunk->rtt_in_progress) { |
| 1265 | rtt = jiffies - tchunk->sent_at; |
| 1266 | sctp_transport_update_rto(transport, |
| 1267 | rtt); |
| 1268 | } |
| 1269 | } |
| 1270 | if (TSN_lte(tsn, sack_ctsn)) { |
| 1271 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
| 1272 | * |
| 1273 | * R3) Whenever a SACK is received |
| 1274 | * that acknowledges the DATA chunk |
| 1275 | * with the earliest outstanding TSN |
| 1276 | * for that address, restart T3-rtx |
| 1277 | * timer for that address with its |
| 1278 | * current RTO. |
| 1279 | */ |
| 1280 | restart_timer = 1; |
| 1281 | |
| 1282 | if (!tchunk->tsn_gap_acked) { |
| 1283 | tchunk->tsn_gap_acked = 1; |
| 1284 | bytes_acked += sctp_data_size(tchunk); |
| 1285 | /* |
| 1286 | * SFR-CACC algorithm: |
| 1287 | * 2) If the SACK contains gap acks |
| 1288 | * and the flag CHANGEOVER_ACTIVE is |
| 1289 | * set the receiver of the SACK MUST |
| 1290 | * take the following action: |
| 1291 | * |
| 1292 | * B) For each TSN t being acked that |
| 1293 | * has not been acked in any SACK so |
| 1294 | * far, set cacc_saw_newack to 1 for |
| 1295 | * the destination that the TSN was |
| 1296 | * sent to. |
| 1297 | */ |
| 1298 | if (transport && |
| 1299 | sack->num_gap_ack_blocks && |
| 1300 | q->asoc->peer.primary_path->cacc. |
| 1301 | changeover_active) |
| 1302 | transport->cacc.cacc_saw_newack |
| 1303 | = 1; |
| 1304 | } |
| 1305 | |
| 1306 | list_add_tail(&tchunk->transmitted_list, |
| 1307 | &q->sacked); |
| 1308 | } else { |
| 1309 | /* RFC2960 7.2.4, sctpimpguide-05 2.8.2 |
| 1310 | * M2) Each time a SACK arrives reporting |
| 1311 | * 'Stray DATA chunk(s)' record the highest TSN |
| 1312 | * reported as newly acknowledged, call this |
| 1313 | * value 'HighestTSNinSack'. A newly |
| 1314 | * acknowledged DATA chunk is one not |
| 1315 | * previously acknowledged in a SACK. |
| 1316 | * |
| 1317 | * When the SCTP sender of data receives a SACK |
| 1318 | * chunk that acknowledges, for the first time, |
| 1319 | * the receipt of a DATA chunk, all the still |
| 1320 | * unacknowledged DATA chunks whose TSN is |
| 1321 | * older than that newly acknowledged DATA |
| 1322 | * chunk, are qualified as 'Stray DATA chunks'. |
| 1323 | */ |
| 1324 | if (!tchunk->tsn_gap_acked) { |
| 1325 | tchunk->tsn_gap_acked = 1; |
| 1326 | bytes_acked += sctp_data_size(tchunk); |
| 1327 | } |
| 1328 | list_add_tail(lchunk, &tlist); |
| 1329 | } |
| 1330 | |
| 1331 | #if SCTP_DEBUG |
| 1332 | switch (dbg_prt_state) { |
| 1333 | case 0: /* last TSN was ACKed */ |
| 1334 | if (dbg_last_ack_tsn + 1 == tsn) { |
| 1335 | /* This TSN belongs to the |
| 1336 | * current ACK range. |
| 1337 | */ |
| 1338 | break; |
| 1339 | } |
| 1340 | |
| 1341 | if (dbg_last_ack_tsn != dbg_ack_tsn) { |
| 1342 | /* Display the end of the |
| 1343 | * current range. |
| 1344 | */ |
| 1345 | SCTP_DEBUG_PRINTK("-%08x", |
| 1346 | dbg_last_ack_tsn); |
| 1347 | } |
| 1348 | |
| 1349 | /* Start a new range. */ |
| 1350 | SCTP_DEBUG_PRINTK(",%08x", tsn); |
| 1351 | dbg_ack_tsn = tsn; |
| 1352 | break; |
| 1353 | |
| 1354 | case 1: /* The last TSN was NOT ACKed. */ |
| 1355 | if (dbg_last_kept_tsn != dbg_kept_tsn) { |
| 1356 | /* Display the end of current range. */ |
| 1357 | SCTP_DEBUG_PRINTK("-%08x", |
| 1358 | dbg_last_kept_tsn); |
| 1359 | } |
| 1360 | |
| 1361 | SCTP_DEBUG_PRINTK("\n"); |
| 1362 | |
| 1363 | /* FALL THROUGH... */ |
| 1364 | default: |
| 1365 | /* This is the first-ever TSN we examined. */ |
| 1366 | /* Start a new range of ACK-ed TSNs. */ |
| 1367 | SCTP_DEBUG_PRINTK("ACKed: %08x", tsn); |
| 1368 | dbg_prt_state = 0; |
| 1369 | dbg_ack_tsn = tsn; |
| 1370 | }; |
| 1371 | |
| 1372 | dbg_last_ack_tsn = tsn; |
| 1373 | #endif /* SCTP_DEBUG */ |
| 1374 | |
| 1375 | } else { |
| 1376 | if (tchunk->tsn_gap_acked) { |
| 1377 | SCTP_DEBUG_PRINTK("%s: Receiver reneged on " |
| 1378 | "data TSN: 0x%x\n", |
| 1379 | __FUNCTION__, |
| 1380 | tsn); |
| 1381 | tchunk->tsn_gap_acked = 0; |
| 1382 | |
| 1383 | bytes_acked -= sctp_data_size(tchunk); |
| 1384 | |
| 1385 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
| 1386 | * |
| 1387 | * R4) Whenever a SACK is received missing a |
| 1388 | * TSN that was previously acknowledged via a |
| 1389 | * Gap Ack Block, start T3-rtx for the |
| 1390 | * destination address to which the DATA |
| 1391 | * chunk was originally |
| 1392 | * transmitted if it is not already running. |
| 1393 | */ |
| 1394 | restart_timer = 1; |
| 1395 | } |
| 1396 | |
| 1397 | list_add_tail(lchunk, &tlist); |
| 1398 | |
| 1399 | #if SCTP_DEBUG |
| 1400 | /* See the above comments on ACK-ed TSNs. */ |
| 1401 | switch (dbg_prt_state) { |
| 1402 | case 1: |
| 1403 | if (dbg_last_kept_tsn + 1 == tsn) |
| 1404 | break; |
| 1405 | |
| 1406 | if (dbg_last_kept_tsn != dbg_kept_tsn) |
| 1407 | SCTP_DEBUG_PRINTK("-%08x", |
| 1408 | dbg_last_kept_tsn); |
| 1409 | |
| 1410 | SCTP_DEBUG_PRINTK(",%08x", tsn); |
| 1411 | dbg_kept_tsn = tsn; |
| 1412 | break; |
| 1413 | |
| 1414 | case 0: |
| 1415 | if (dbg_last_ack_tsn != dbg_ack_tsn) |
| 1416 | SCTP_DEBUG_PRINTK("-%08x", |
| 1417 | dbg_last_ack_tsn); |
| 1418 | SCTP_DEBUG_PRINTK("\n"); |
| 1419 | |
| 1420 | /* FALL THROUGH... */ |
| 1421 | default: |
| 1422 | SCTP_DEBUG_PRINTK("KEPT: %08x",tsn); |
| 1423 | dbg_prt_state = 1; |
| 1424 | dbg_kept_tsn = tsn; |
| 1425 | }; |
| 1426 | |
| 1427 | dbg_last_kept_tsn = tsn; |
| 1428 | #endif /* SCTP_DEBUG */ |
| 1429 | } |
| 1430 | } |
| 1431 | |
| 1432 | #if SCTP_DEBUG |
| 1433 | /* Finish off the last range, displaying its ending TSN. */ |
| 1434 | switch (dbg_prt_state) { |
| 1435 | case 0: |
| 1436 | if (dbg_last_ack_tsn != dbg_ack_tsn) { |
| 1437 | SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn); |
| 1438 | } else { |
| 1439 | SCTP_DEBUG_PRINTK("\n"); |
| 1440 | } |
| 1441 | break; |
| 1442 | |
| 1443 | case 1: |
| 1444 | if (dbg_last_kept_tsn != dbg_kept_tsn) { |
| 1445 | SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn); |
| 1446 | } else { |
| 1447 | SCTP_DEBUG_PRINTK("\n"); |
| 1448 | } |
| 1449 | }; |
| 1450 | #endif /* SCTP_DEBUG */ |
| 1451 | if (transport) { |
| 1452 | if (bytes_acked) { |
| 1453 | /* 8.2. When an outstanding TSN is acknowledged, |
| 1454 | * the endpoint shall clear the error counter of |
| 1455 | * the destination transport address to which the |
| 1456 | * DATA chunk was last sent. |
| 1457 | * The association's overall error counter is |
| 1458 | * also cleared. |
| 1459 | */ |
| 1460 | transport->error_count = 0; |
| 1461 | transport->asoc->overall_error_count = 0; |
| 1462 | |
| 1463 | /* Mark the destination transport address as |
| 1464 | * active if it is not so marked. |
| 1465 | */ |
Frank Filz | 3f7a87d | 2005-06-20 13:14:57 -0700 | [diff] [blame] | 1466 | if (transport->state == SCTP_INACTIVE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | sctp_assoc_control_transport( |
| 1468 | transport->asoc, |
| 1469 | transport, |
| 1470 | SCTP_TRANSPORT_UP, |
| 1471 | SCTP_RECEIVED_SACK); |
| 1472 | } |
| 1473 | |
| 1474 | sctp_transport_raise_cwnd(transport, sack_ctsn, |
| 1475 | bytes_acked); |
| 1476 | |
| 1477 | transport->flight_size -= bytes_acked; |
| 1478 | q->outstanding_bytes -= bytes_acked; |
| 1479 | } else { |
| 1480 | /* RFC 2960 6.1, sctpimpguide-06 2.15.2 |
| 1481 | * When a sender is doing zero window probing, it |
| 1482 | * should not timeout the association if it continues |
| 1483 | * to receive new packets from the receiver. The |
| 1484 | * reason is that the receiver MAY keep its window |
| 1485 | * closed for an indefinite time. |
| 1486 | * A sender is doing zero window probing when the |
| 1487 | * receiver's advertised window is zero, and there is |
| 1488 | * only one data chunk in flight to the receiver. |
| 1489 | */ |
| 1490 | if (!q->asoc->peer.rwnd && |
| 1491 | !list_empty(&tlist) && |
| 1492 | (sack_ctsn+2 == q->asoc->next_tsn)) { |
| 1493 | SCTP_DEBUG_PRINTK("%s: SACK received for zero " |
| 1494 | "window probe: %u\n", |
| 1495 | __FUNCTION__, sack_ctsn); |
| 1496 | q->asoc->overall_error_count = 0; |
| 1497 | transport->error_count = 0; |
| 1498 | } |
| 1499 | } |
| 1500 | |
| 1501 | /* RFC 2960 6.3.2 Retransmission Timer Rules |
| 1502 | * |
| 1503 | * R2) Whenever all outstanding data sent to an address have |
| 1504 | * been acknowledged, turn off the T3-rtx timer of that |
| 1505 | * address. |
| 1506 | */ |
| 1507 | if (!transport->flight_size) { |
| 1508 | if (timer_pending(&transport->T3_rtx_timer) && |
| 1509 | del_timer(&transport->T3_rtx_timer)) { |
| 1510 | sctp_transport_put(transport); |
| 1511 | } |
| 1512 | } else if (restart_timer) { |
| 1513 | if (!mod_timer(&transport->T3_rtx_timer, |
| 1514 | jiffies + transport->rto)) |
| 1515 | sctp_transport_hold(transport); |
| 1516 | } |
| 1517 | } |
| 1518 | |
| 1519 | list_splice(&tlist, transmitted_queue); |
| 1520 | } |
| 1521 | |
| 1522 | /* Mark chunks as missing and consequently may get retransmitted. */ |
| 1523 | static void sctp_mark_missing(struct sctp_outq *q, |
| 1524 | struct list_head *transmitted_queue, |
| 1525 | struct sctp_transport *transport, |
| 1526 | __u32 highest_new_tsn_in_sack, |
| 1527 | int count_of_newacks) |
| 1528 | { |
| 1529 | struct sctp_chunk *chunk; |
| 1530 | struct list_head *pos; |
| 1531 | __u32 tsn; |
| 1532 | char do_fast_retransmit = 0; |
| 1533 | struct sctp_transport *primary = q->asoc->peer.primary_path; |
| 1534 | |
| 1535 | list_for_each(pos, transmitted_queue) { |
| 1536 | |
| 1537 | chunk = list_entry(pos, struct sctp_chunk, transmitted_list); |
| 1538 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
| 1539 | |
| 1540 | /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all |
| 1541 | * 'Unacknowledged TSN's', if the TSN number of an |
| 1542 | * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack' |
| 1543 | * value, increment the 'TSN.Missing.Report' count on that |
| 1544 | * chunk if it has NOT been fast retransmitted or marked for |
| 1545 | * fast retransmit already. |
| 1546 | */ |
| 1547 | if (!chunk->fast_retransmit && |
| 1548 | !chunk->tsn_gap_acked && |
| 1549 | TSN_lt(tsn, highest_new_tsn_in_sack)) { |
| 1550 | |
| 1551 | /* SFR-CACC may require us to skip marking |
| 1552 | * this chunk as missing. |
| 1553 | */ |
| 1554 | if (!transport || !sctp_cacc_skip(primary, transport, |
| 1555 | count_of_newacks, tsn)) { |
| 1556 | chunk->tsn_missing_report++; |
| 1557 | |
| 1558 | SCTP_DEBUG_PRINTK( |
| 1559 | "%s: TSN 0x%x missing counter: %d\n", |
| 1560 | __FUNCTION__, tsn, |
| 1561 | chunk->tsn_missing_report); |
| 1562 | } |
| 1563 | } |
| 1564 | /* |
| 1565 | * M4) If any DATA chunk is found to have a |
| 1566 | * 'TSN.Missing.Report' |
Vlad Yasevich | 27852c2 | 2006-02-02 16:57:31 -0800 | [diff] [blame^] | 1567 | * value larger than or equal to 3, mark that chunk for |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1568 | * retransmission and start the fast retransmit procedure. |
| 1569 | */ |
| 1570 | |
Vlad Yasevich | 27852c2 | 2006-02-02 16:57:31 -0800 | [diff] [blame^] | 1571 | if (chunk->tsn_missing_report >= 3) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1572 | chunk->fast_retransmit = 1; |
| 1573 | do_fast_retransmit = 1; |
| 1574 | } |
| 1575 | } |
| 1576 | |
| 1577 | if (transport) { |
| 1578 | if (do_fast_retransmit) |
| 1579 | sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX); |
| 1580 | |
| 1581 | SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, " |
| 1582 | "ssthresh: %d, flight_size: %d, pba: %d\n", |
| 1583 | __FUNCTION__, transport, transport->cwnd, |
| 1584 | transport->ssthresh, transport->flight_size, |
| 1585 | transport->partial_bytes_acked); |
| 1586 | } |
| 1587 | } |
| 1588 | |
| 1589 | /* Is the given TSN acked by this packet? */ |
| 1590 | static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) |
| 1591 | { |
| 1592 | int i; |
| 1593 | sctp_sack_variable_t *frags; |
| 1594 | __u16 gap; |
| 1595 | __u32 ctsn = ntohl(sack->cum_tsn_ack); |
| 1596 | |
| 1597 | if (TSN_lte(tsn, ctsn)) |
| 1598 | goto pass; |
| 1599 | |
| 1600 | /* 3.3.4 Selective Acknowledgement (SACK) (3): |
| 1601 | * |
| 1602 | * Gap Ack Blocks: |
| 1603 | * These fields contain the Gap Ack Blocks. They are repeated |
| 1604 | * for each Gap Ack Block up to the number of Gap Ack Blocks |
| 1605 | * defined in the Number of Gap Ack Blocks field. All DATA |
| 1606 | * chunks with TSNs greater than or equal to (Cumulative TSN |
| 1607 | * Ack + Gap Ack Block Start) and less than or equal to |
| 1608 | * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack |
| 1609 | * Block are assumed to have been received correctly. |
| 1610 | */ |
| 1611 | |
| 1612 | frags = sack->variable; |
| 1613 | gap = tsn - ctsn; |
| 1614 | for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) { |
| 1615 | if (TSN_lte(ntohs(frags[i].gab.start), gap) && |
| 1616 | TSN_lte(gap, ntohs(frags[i].gab.end))) |
| 1617 | goto pass; |
| 1618 | } |
| 1619 | |
| 1620 | return 0; |
| 1621 | pass: |
| 1622 | return 1; |
| 1623 | } |
| 1624 | |
| 1625 | static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, |
| 1626 | int nskips, __u16 stream) |
| 1627 | { |
| 1628 | int i; |
| 1629 | |
| 1630 | for (i = 0; i < nskips; i++) { |
| 1631 | if (skiplist[i].stream == stream) |
| 1632 | return i; |
| 1633 | } |
| 1634 | return i; |
| 1635 | } |
| 1636 | |
| 1637 | /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ |
| 1638 | static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) |
| 1639 | { |
| 1640 | struct sctp_association *asoc = q->asoc; |
| 1641 | struct sctp_chunk *ftsn_chunk = NULL; |
| 1642 | struct sctp_fwdtsn_skip ftsn_skip_arr[10]; |
| 1643 | int nskips = 0; |
| 1644 | int skip_pos = 0; |
| 1645 | __u32 tsn; |
| 1646 | struct sctp_chunk *chunk; |
| 1647 | struct list_head *lchunk, *temp; |
| 1648 | |
| 1649 | /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the |
| 1650 | * received SACK. |
| 1651 | * |
| 1652 | * If (Advanced.Peer.Ack.Point < SackCumAck), then update |
| 1653 | * Advanced.Peer.Ack.Point to be equal to SackCumAck. |
| 1654 | */ |
| 1655 | if (TSN_lt(asoc->adv_peer_ack_point, ctsn)) |
| 1656 | asoc->adv_peer_ack_point = ctsn; |
| 1657 | |
| 1658 | /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point" |
| 1659 | * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as |
| 1660 | * the chunk next in the out-queue space is marked as "abandoned" as |
| 1661 | * shown in the following example: |
| 1662 | * |
| 1663 | * Assuming that a SACK arrived with the Cumulative TSN ACK 102 |
| 1664 | * and the Advanced.Peer.Ack.Point is updated to this value: |
| 1665 | * |
| 1666 | * out-queue at the end of ==> out-queue after Adv.Ack.Point |
| 1667 | * normal SACK processing local advancement |
| 1668 | * ... ... |
| 1669 | * Adv.Ack.Pt-> 102 acked 102 acked |
| 1670 | * 103 abandoned 103 abandoned |
| 1671 | * 104 abandoned Adv.Ack.P-> 104 abandoned |
| 1672 | * 105 105 |
| 1673 | * 106 acked 106 acked |
| 1674 | * ... ... |
| 1675 | * |
| 1676 | * In this example, the data sender successfully advanced the |
| 1677 | * "Advanced.Peer.Ack.Point" from 102 to 104 locally. |
| 1678 | */ |
| 1679 | list_for_each_safe(lchunk, temp, &q->abandoned) { |
| 1680 | chunk = list_entry(lchunk, struct sctp_chunk, |
| 1681 | transmitted_list); |
| 1682 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
| 1683 | |
| 1684 | /* Remove any chunks in the abandoned queue that are acked by |
| 1685 | * the ctsn. |
| 1686 | */ |
| 1687 | if (TSN_lte(tsn, ctsn)) { |
| 1688 | list_del_init(lchunk); |
| 1689 | if (!chunk->tsn_gap_acked) { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 1690 | chunk->transport->flight_size -= |
| 1691 | sctp_data_size(chunk); |
| 1692 | q->outstanding_bytes -= sctp_data_size(chunk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1693 | } |
| 1694 | sctp_chunk_free(chunk); |
| 1695 | } else { |
| 1696 | if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) { |
| 1697 | asoc->adv_peer_ack_point = tsn; |
| 1698 | if (chunk->chunk_hdr->flags & |
| 1699 | SCTP_DATA_UNORDERED) |
| 1700 | continue; |
| 1701 | skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], |
| 1702 | nskips, |
| 1703 | chunk->subh.data_hdr->stream); |
| 1704 | ftsn_skip_arr[skip_pos].stream = |
| 1705 | chunk->subh.data_hdr->stream; |
| 1706 | ftsn_skip_arr[skip_pos].ssn = |
| 1707 | chunk->subh.data_hdr->ssn; |
| 1708 | if (skip_pos == nskips) |
| 1709 | nskips++; |
| 1710 | if (nskips == 10) |
| 1711 | break; |
| 1712 | } else |
| 1713 | break; |
| 1714 | } |
| 1715 | } |
| 1716 | |
| 1717 | /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point" |
| 1718 | * is greater than the Cumulative TSN ACK carried in the received |
| 1719 | * SACK, the data sender MUST send the data receiver a FORWARD TSN |
| 1720 | * chunk containing the latest value of the |
| 1721 | * "Advanced.Peer.Ack.Point". |
| 1722 | * |
| 1723 | * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD |
| 1724 | * list each stream and sequence number in the forwarded TSN. This |
| 1725 | * information will enable the receiver to easily find any |
| 1726 | * stranded TSN's waiting on stream reorder queues. Each stream |
| 1727 | * SHOULD only be reported once; this means that if multiple |
| 1728 | * abandoned messages occur in the same stream then only the |
| 1729 | * highest abandoned stream sequence number is reported. If the |
| 1730 | * total size of the FORWARD TSN does NOT fit in a single MTU then |
| 1731 | * the sender of the FORWARD TSN SHOULD lower the |
| 1732 | * Advanced.Peer.Ack.Point to the last TSN that will fit in a |
| 1733 | * single MTU. |
| 1734 | */ |
| 1735 | if (asoc->adv_peer_ack_point > ctsn) |
| 1736 | ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point, |
| 1737 | nskips, &ftsn_skip_arr[0]); |
| 1738 | |
| 1739 | if (ftsn_chunk) { |
David S. Miller | 79af02c | 2005-07-08 21:47:49 -0700 | [diff] [blame] | 1740 | list_add_tail(&ftsn_chunk->list, &q->control_chunk_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 1742 | } |
| 1743 | } |