1 /* Management of Tx window, Tx resend, ACKs and out-of-sequence reception
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #include <linux/module.h>
13 #include <linux/circ_buf.h>
14 #include <linux/net.h>
15 #include <linux/skbuff.h>
16 #include <linux/slab.h>
17 #include <linux/udp.h>
18 #include <net/sock.h>
19 #include <net/af_rxrpc.h>
20 #include "ar-internal.h"
21
22 /*
23 * How long to wait before scheduling ACK generation after seeing a
24 * packet with RXRPC_REQUEST_ACK set (in jiffies).
25 */
26 unsigned rxrpc_requested_ack_delay = 1;
27
28 /*
29 * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
30 *
31 * We use this when we've received new data packets. If those packets aren't
32 * all consumed within this time we will send a DELAY ACK if an ACK was not
33 * requested to let the sender know it doesn't need to resend.
34 */
35 unsigned rxrpc_soft_ack_delay = 1 * HZ;
36
37 /*
38 * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
39 *
40 * We use this when we've consumed some previously soft-ACK'd packets when
41 * further packets aren't immediately received to decide when to send an IDLE
42 * ACK let the other end know that it can free up its Tx buffer space.
43 */
44 unsigned rxrpc_idle_ack_delay = 0.5 * HZ;
45
46 /*
47 * Receive window size in packets. This indicates the maximum number of
48 * unconsumed received packets we're willing to retain in memory. Once this
49 * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
50 * packets.
51 */
52 unsigned rxrpc_rx_window_size = 32;
53
54 /*
55 * Maximum Rx MTU size. This indicates to the sender the size of jumbo packet
56 * made by gluing normal packets together that we're willing to handle.
57 */
58 unsigned rxrpc_rx_mtu = 5692;
59
60 /*
61 * The maximum number of fragments in a received jumbo packet that we tell the
62 * sender that we're willing to handle.
63 */
64 unsigned rxrpc_rx_jumbo_max = 4;
65
rxrpc_acks(u8 reason)66 static const char *rxrpc_acks(u8 reason)
67 {
68 static const char *const str[] = {
69 "---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
70 "IDL", "-?-"
71 };
72
73 if (reason >= ARRAY_SIZE(str))
74 reason = ARRAY_SIZE(str) - 1;
75 return str[reason];
76 }
77
78 static const s8 rxrpc_ack_priority[] = {
79 [0] = 0,
80 [RXRPC_ACK_DELAY] = 1,
81 [RXRPC_ACK_REQUESTED] = 2,
82 [RXRPC_ACK_IDLE] = 3,
83 [RXRPC_ACK_PING_RESPONSE] = 4,
84 [RXRPC_ACK_DUPLICATE] = 5,
85 [RXRPC_ACK_OUT_OF_SEQUENCE] = 6,
86 [RXRPC_ACK_EXCEEDS_WINDOW] = 7,
87 [RXRPC_ACK_NOSPACE] = 8,
88 };
89
90 /*
91 * propose an ACK be sent
92 */
__rxrpc_propose_ACK(struct rxrpc_call * call,u8 ack_reason,__be32 serial,bool immediate)93 void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
94 __be32 serial, bool immediate)
95 {
96 unsigned long expiry;
97 s8 prior = rxrpc_ack_priority[ack_reason];
98
99 ASSERTCMP(prior, >, 0);
100
101 _enter("{%d},%s,%%%x,%u",
102 call->debug_id, rxrpc_acks(ack_reason), ntohl(serial),
103 immediate);
104
105 if (prior < rxrpc_ack_priority[call->ackr_reason]) {
106 if (immediate)
107 goto cancel_timer;
108 return;
109 }
110
111 /* update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial
112 * numbers */
113 if (prior == rxrpc_ack_priority[call->ackr_reason]) {
114 if (prior <= 4)
115 call->ackr_serial = serial;
116 if (immediate)
117 goto cancel_timer;
118 return;
119 }
120
121 call->ackr_reason = ack_reason;
122 call->ackr_serial = serial;
123
124 switch (ack_reason) {
125 case RXRPC_ACK_DELAY:
126 _debug("run delay timer");
127 expiry = rxrpc_soft_ack_delay;
128 goto run_timer;
129
130 case RXRPC_ACK_IDLE:
131 if (!immediate) {
132 _debug("run defer timer");
133 expiry = rxrpc_idle_ack_delay;
134 goto run_timer;
135 }
136 goto cancel_timer;
137
138 case RXRPC_ACK_REQUESTED:
139 expiry = rxrpc_requested_ack_delay;
140 if (!expiry)
141 goto cancel_timer;
142 if (!immediate || serial == cpu_to_be32(1)) {
143 _debug("run defer timer");
144 goto run_timer;
145 }
146
147 default:
148 _debug("immediate ACK");
149 goto cancel_timer;
150 }
151
152 run_timer:
153 expiry += jiffies;
154 if (!timer_pending(&call->ack_timer) ||
155 time_after(call->ack_timer.expires, expiry))
156 mod_timer(&call->ack_timer, expiry);
157 return;
158
159 cancel_timer:
160 _debug("cancel timer %%%u", ntohl(serial));
161 try_to_del_timer_sync(&call->ack_timer);
162 read_lock_bh(&call->state_lock);
163 if (call->state <= RXRPC_CALL_COMPLETE &&
164 !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
165 rxrpc_queue_call(call);
166 read_unlock_bh(&call->state_lock);
167 }
168
169 /*
170 * propose an ACK be sent, locking the call structure
171 */
rxrpc_propose_ACK(struct rxrpc_call * call,u8 ack_reason,__be32 serial,bool immediate)172 void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
173 __be32 serial, bool immediate)
174 {
175 s8 prior = rxrpc_ack_priority[ack_reason];
176
177 if (prior > rxrpc_ack_priority[call->ackr_reason]) {
178 spin_lock_bh(&call->lock);
179 __rxrpc_propose_ACK(call, ack_reason, serial, immediate);
180 spin_unlock_bh(&call->lock);
181 }
182 }
183
184 /*
185 * set the resend timer
186 */
rxrpc_set_resend(struct rxrpc_call * call,u8 resend,unsigned long resend_at)187 static void rxrpc_set_resend(struct rxrpc_call *call, u8 resend,
188 unsigned long resend_at)
189 {
190 read_lock_bh(&call->state_lock);
191 if (call->state >= RXRPC_CALL_COMPLETE)
192 resend = 0;
193
194 if (resend & 1) {
195 _debug("SET RESEND");
196 set_bit(RXRPC_CALL_RESEND, &call->events);
197 }
198
199 if (resend & 2) {
200 _debug("MODIFY RESEND TIMER");
201 set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
202 mod_timer(&call->resend_timer, resend_at);
203 } else {
204 _debug("KILL RESEND TIMER");
205 del_timer_sync(&call->resend_timer);
206 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
207 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
208 }
209 read_unlock_bh(&call->state_lock);
210 }
211
212 /*
213 * resend packets
214 */
rxrpc_resend(struct rxrpc_call * call)215 static void rxrpc_resend(struct rxrpc_call *call)
216 {
217 struct rxrpc_skb_priv *sp;
218 struct rxrpc_header *hdr;
219 struct sk_buff *txb;
220 unsigned long *p_txb, resend_at;
221 bool stop;
222 int loop;
223 u8 resend;
224
225 _enter("{%d,%d,%d,%d},",
226 call->acks_hard, call->acks_unacked,
227 atomic_read(&call->sequence),
228 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
229
230 stop = false;
231 resend = 0;
232 resend_at = 0;
233
234 for (loop = call->acks_tail;
235 loop != call->acks_head || stop;
236 loop = (loop + 1) & (call->acks_winsz - 1)
237 ) {
238 p_txb = call->acks_window + loop;
239 smp_read_barrier_depends();
240 if (*p_txb & 1)
241 continue;
242
243 txb = (struct sk_buff *) *p_txb;
244 sp = rxrpc_skb(txb);
245
246 if (sp->need_resend) {
247 sp->need_resend = false;
248
249 /* each Tx packet has a new serial number */
250 sp->hdr.serial =
251 htonl(atomic_inc_return(&call->conn->serial));
252
253 hdr = (struct rxrpc_header *) txb->head;
254 hdr->serial = sp->hdr.serial;
255
256 _proto("Tx DATA %%%u { #%d }",
257 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
258 if (rxrpc_send_packet(call->conn->trans, txb) < 0) {
259 stop = true;
260 sp->resend_at = jiffies + 3;
261 } else {
262 sp->resend_at =
263 jiffies + rxrpc_resend_timeout;
264 }
265 }
266
267 if (time_after_eq(jiffies + 1, sp->resend_at)) {
268 sp->need_resend = true;
269 resend |= 1;
270 } else if (resend & 2) {
271 if (time_before(sp->resend_at, resend_at))
272 resend_at = sp->resend_at;
273 } else {
274 resend_at = sp->resend_at;
275 resend |= 2;
276 }
277 }
278
279 rxrpc_set_resend(call, resend, resend_at);
280 _leave("");
281 }
282
283 /*
284 * handle resend timer expiry
285 */
rxrpc_resend_timer(struct rxrpc_call * call)286 static void rxrpc_resend_timer(struct rxrpc_call *call)
287 {
288 struct rxrpc_skb_priv *sp;
289 struct sk_buff *txb;
290 unsigned long *p_txb, resend_at;
291 int loop;
292 u8 resend;
293
294 _enter("%d,%d,%d",
295 call->acks_tail, call->acks_unacked, call->acks_head);
296
297 if (call->state >= RXRPC_CALL_COMPLETE)
298 return;
299
300 resend = 0;
301 resend_at = 0;
302
303 for (loop = call->acks_unacked;
304 loop != call->acks_head;
305 loop = (loop + 1) & (call->acks_winsz - 1)
306 ) {
307 p_txb = call->acks_window + loop;
308 smp_read_barrier_depends();
309 txb = (struct sk_buff *) (*p_txb & ~1);
310 sp = rxrpc_skb(txb);
311
312 ASSERT(!(*p_txb & 1));
313
314 if (sp->need_resend) {
315 ;
316 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
317 sp->need_resend = true;
318 resend |= 1;
319 } else if (resend & 2) {
320 if (time_before(sp->resend_at, resend_at))
321 resend_at = sp->resend_at;
322 } else {
323 resend_at = sp->resend_at;
324 resend |= 2;
325 }
326 }
327
328 rxrpc_set_resend(call, resend, resend_at);
329 _leave("");
330 }
331
332 /*
333 * process soft ACKs of our transmitted packets
334 * - these indicate packets the peer has or has not received, but hasn't yet
335 * given to the consumer, and so can still be discarded and re-requested
336 */
rxrpc_process_soft_ACKs(struct rxrpc_call * call,struct rxrpc_ackpacket * ack,struct sk_buff * skb)337 static int rxrpc_process_soft_ACKs(struct rxrpc_call *call,
338 struct rxrpc_ackpacket *ack,
339 struct sk_buff *skb)
340 {
341 struct rxrpc_skb_priv *sp;
342 struct sk_buff *txb;
343 unsigned long *p_txb, resend_at;
344 int loop;
345 u8 sacks[RXRPC_MAXACKS], resend;
346
347 _enter("{%d,%d},{%d},",
348 call->acks_hard,
349 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz),
350 ack->nAcks);
351
352 if (skb_copy_bits(skb, 0, sacks, ack->nAcks) < 0)
353 goto protocol_error;
354
355 resend = 0;
356 resend_at = 0;
357 for (loop = 0; loop < ack->nAcks; loop++) {
358 p_txb = call->acks_window;
359 p_txb += (call->acks_tail + loop) & (call->acks_winsz - 1);
360 smp_read_barrier_depends();
361 txb = (struct sk_buff *) (*p_txb & ~1);
362 sp = rxrpc_skb(txb);
363
364 switch (sacks[loop]) {
365 case RXRPC_ACK_TYPE_ACK:
366 sp->need_resend = false;
367 *p_txb |= 1;
368 break;
369 case RXRPC_ACK_TYPE_NACK:
370 sp->need_resend = true;
371 *p_txb &= ~1;
372 resend = 1;
373 break;
374 default:
375 _debug("Unsupported ACK type %d", sacks[loop]);
376 goto protocol_error;
377 }
378 }
379
380 smp_mb();
381 call->acks_unacked = (call->acks_tail + loop) & (call->acks_winsz - 1);
382
383 /* anything not explicitly ACK'd is implicitly NACK'd, but may just not
384 * have been received or processed yet by the far end */
385 for (loop = call->acks_unacked;
386 loop != call->acks_head;
387 loop = (loop + 1) & (call->acks_winsz - 1)
388 ) {
389 p_txb = call->acks_window + loop;
390 smp_read_barrier_depends();
391 txb = (struct sk_buff *) (*p_txb & ~1);
392 sp = rxrpc_skb(txb);
393
394 if (*p_txb & 1) {
395 /* packet must have been discarded */
396 sp->need_resend = true;
397 *p_txb &= ~1;
398 resend |= 1;
399 } else if (sp->need_resend) {
400 ;
401 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
402 sp->need_resend = true;
403 resend |= 1;
404 } else if (resend & 2) {
405 if (time_before(sp->resend_at, resend_at))
406 resend_at = sp->resend_at;
407 } else {
408 resend_at = sp->resend_at;
409 resend |= 2;
410 }
411 }
412
413 rxrpc_set_resend(call, resend, resend_at);
414 _leave(" = 0");
415 return 0;
416
417 protocol_error:
418 _leave(" = -EPROTO");
419 return -EPROTO;
420 }
421
422 /*
423 * discard hard-ACK'd packets from the Tx window
424 */
rxrpc_rotate_tx_window(struct rxrpc_call * call,u32 hard)425 static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard)
426 {
427 unsigned long _skb;
428 int tail = call->acks_tail, old_tail;
429 int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz);
430
431 _enter("{%u,%u},%u", call->acks_hard, win, hard);
432
433 ASSERTCMP(hard - call->acks_hard, <=, win);
434
435 while (call->acks_hard < hard) {
436 smp_read_barrier_depends();
437 _skb = call->acks_window[tail] & ~1;
438 rxrpc_free_skb((struct sk_buff *) _skb);
439 old_tail = tail;
440 tail = (tail + 1) & (call->acks_winsz - 1);
441 call->acks_tail = tail;
442 if (call->acks_unacked == old_tail)
443 call->acks_unacked = tail;
444 call->acks_hard++;
445 }
446
447 wake_up(&call->tx_waitq);
448 }
449
450 /*
451 * clear the Tx window in the event of a failure
452 */
rxrpc_clear_tx_window(struct rxrpc_call * call)453 static void rxrpc_clear_tx_window(struct rxrpc_call *call)
454 {
455 rxrpc_rotate_tx_window(call, atomic_read(&call->sequence));
456 }
457
458 /*
459 * drain the out of sequence received packet queue into the packet Rx queue
460 */
rxrpc_drain_rx_oos_queue(struct rxrpc_call * call)461 static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call)
462 {
463 struct rxrpc_skb_priv *sp;
464 struct sk_buff *skb;
465 bool terminal;
466 int ret;
467
468 _enter("{%d,%d}", call->rx_data_post, call->rx_first_oos);
469
470 spin_lock_bh(&call->lock);
471
472 ret = -ECONNRESET;
473 if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
474 goto socket_unavailable;
475
476 skb = skb_dequeue(&call->rx_oos_queue);
477 if (skb) {
478 sp = rxrpc_skb(skb);
479
480 _debug("drain OOS packet %d [%d]",
481 ntohl(sp->hdr.seq), call->rx_first_oos);
482
483 if (ntohl(sp->hdr.seq) != call->rx_first_oos) {
484 skb_queue_head(&call->rx_oos_queue, skb);
485 call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq);
486 _debug("requeue %p {%u}", skb, call->rx_first_oos);
487 } else {
488 skb->mark = RXRPC_SKB_MARK_DATA;
489 terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
490 !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
491 ret = rxrpc_queue_rcv_skb(call, skb, true, terminal);
492 BUG_ON(ret < 0);
493 _debug("drain #%u", call->rx_data_post);
494 call->rx_data_post++;
495
496 /* find out what the next packet is */
497 skb = skb_peek(&call->rx_oos_queue);
498 if (skb)
499 call->rx_first_oos =
500 ntohl(rxrpc_skb(skb)->hdr.seq);
501 else
502 call->rx_first_oos = 0;
503 _debug("peek %p {%u}", skb, call->rx_first_oos);
504 }
505 }
506
507 ret = 0;
508 socket_unavailable:
509 spin_unlock_bh(&call->lock);
510 _leave(" = %d", ret);
511 return ret;
512 }
513
514 /*
515 * insert an out of sequence packet into the buffer
516 */
rxrpc_insert_oos_packet(struct rxrpc_call * call,struct sk_buff * skb)517 static void rxrpc_insert_oos_packet(struct rxrpc_call *call,
518 struct sk_buff *skb)
519 {
520 struct rxrpc_skb_priv *sp, *psp;
521 struct sk_buff *p;
522 u32 seq;
523
524 sp = rxrpc_skb(skb);
525 seq = ntohl(sp->hdr.seq);
526 _enter(",,{%u}", seq);
527
528 skb->destructor = rxrpc_packet_destructor;
529 ASSERTCMP(sp->call, ==, NULL);
530 sp->call = call;
531 rxrpc_get_call(call);
532
533 /* insert into the buffer in sequence order */
534 spin_lock_bh(&call->lock);
535
536 skb_queue_walk(&call->rx_oos_queue, p) {
537 psp = rxrpc_skb(p);
538 if (ntohl(psp->hdr.seq) > seq) {
539 _debug("insert oos #%u before #%u",
540 seq, ntohl(psp->hdr.seq));
541 skb_insert(p, skb, &call->rx_oos_queue);
542 goto inserted;
543 }
544 }
545
546 _debug("append oos #%u", seq);
547 skb_queue_tail(&call->rx_oos_queue, skb);
548 inserted:
549
550 /* we might now have a new front to the queue */
551 if (call->rx_first_oos == 0 || seq < call->rx_first_oos)
552 call->rx_first_oos = seq;
553
554 read_lock(&call->state_lock);
555 if (call->state < RXRPC_CALL_COMPLETE &&
556 call->rx_data_post == call->rx_first_oos) {
557 _debug("drain rx oos now");
558 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
559 }
560 read_unlock(&call->state_lock);
561
562 spin_unlock_bh(&call->lock);
563 _leave(" [stored #%u]", call->rx_first_oos);
564 }
565
566 /*
567 * clear the Tx window on final ACK reception
568 */
rxrpc_zap_tx_window(struct rxrpc_call * call)569 static void rxrpc_zap_tx_window(struct rxrpc_call *call)
570 {
571 struct rxrpc_skb_priv *sp;
572 struct sk_buff *skb;
573 unsigned long _skb, *acks_window;
574 u8 winsz = call->acks_winsz;
575 int tail;
576
577 acks_window = call->acks_window;
578 call->acks_window = NULL;
579
580 while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) {
581 tail = call->acks_tail;
582 smp_read_barrier_depends();
583 _skb = acks_window[tail] & ~1;
584 smp_mb();
585 call->acks_tail = (call->acks_tail + 1) & (winsz - 1);
586
587 skb = (struct sk_buff *) _skb;
588 sp = rxrpc_skb(skb);
589 _debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
590 rxrpc_free_skb(skb);
591 }
592
593 kfree(acks_window);
594 }
595
596 /*
597 * process the extra information that may be appended to an ACK packet
598 */
rxrpc_extract_ackinfo(struct rxrpc_call * call,struct sk_buff * skb,unsigned int latest,int nAcks)599 static void rxrpc_extract_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
600 unsigned int latest, int nAcks)
601 {
602 struct rxrpc_ackinfo ackinfo;
603 struct rxrpc_peer *peer;
604 unsigned int mtu;
605
606 if (skb_copy_bits(skb, nAcks + 3, &ackinfo, sizeof(ackinfo)) < 0) {
607 _leave(" [no ackinfo]");
608 return;
609 }
610
611 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
612 latest,
613 ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU),
614 ntohl(ackinfo.rwind), ntohl(ackinfo.jumbo_max));
615
616 mtu = min(ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU));
617
618 peer = call->conn->trans->peer;
619 if (mtu < peer->maxdata) {
620 spin_lock_bh(&peer->lock);
621 peer->maxdata = mtu;
622 peer->mtu = mtu + peer->hdrsize;
623 spin_unlock_bh(&peer->lock);
624 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
625 }
626 }
627
628 /*
629 * process packets in the reception queue
630 */
rxrpc_process_rx_queue(struct rxrpc_call * call,u32 * _abort_code)631 static int rxrpc_process_rx_queue(struct rxrpc_call *call,
632 u32 *_abort_code)
633 {
634 struct rxrpc_ackpacket ack;
635 struct rxrpc_skb_priv *sp;
636 struct sk_buff *skb;
637 bool post_ACK;
638 int latest;
639 u32 hard, tx;
640
641 _enter("");
642
643 process_further:
644 skb = skb_dequeue(&call->rx_queue);
645 if (!skb)
646 return -EAGAIN;
647
648 _net("deferred skb %p", skb);
649
650 sp = rxrpc_skb(skb);
651
652 _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state);
653
654 post_ACK = false;
655
656 switch (sp->hdr.type) {
657 /* data packets that wind up here have been received out of
658 * order, need security processing or are jumbo packets */
659 case RXRPC_PACKET_TYPE_DATA:
660 _proto("OOSQ DATA %%%u { #%u }",
661 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
662
663 /* secured packets must be verified and possibly decrypted */
664 if (rxrpc_verify_packet(call, skb, _abort_code) < 0)
665 goto protocol_error;
666
667 rxrpc_insert_oos_packet(call, skb);
668 goto process_further;
669
670 /* partial ACK to process */
671 case RXRPC_PACKET_TYPE_ACK:
672 if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) {
673 _debug("extraction failure");
674 goto protocol_error;
675 }
676 if (!skb_pull(skb, sizeof(ack)))
677 BUG();
678
679 latest = ntohl(sp->hdr.serial);
680 hard = ntohl(ack.firstPacket);
681 tx = atomic_read(&call->sequence);
682
683 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
684 latest,
685 ntohs(ack.maxSkew),
686 hard,
687 ntohl(ack.previousPacket),
688 ntohl(ack.serial),
689 rxrpc_acks(ack.reason),
690 ack.nAcks);
691
692 rxrpc_extract_ackinfo(call, skb, latest, ack.nAcks);
693
694 if (ack.reason == RXRPC_ACK_PING) {
695 _proto("Rx ACK %%%u PING Request", latest);
696 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
697 sp->hdr.serial, true);
698 }
699
700 /* discard any out-of-order or duplicate ACKs */
701 if (latest - call->acks_latest <= 0) {
702 _debug("discard ACK %d <= %d",
703 latest, call->acks_latest);
704 goto discard;
705 }
706 call->acks_latest = latest;
707
708 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
709 call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY &&
710 call->state != RXRPC_CALL_SERVER_SEND_REPLY &&
711 call->state != RXRPC_CALL_SERVER_AWAIT_ACK)
712 goto discard;
713
714 _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state);
715
716 if (hard > 0) {
717 if (hard - 1 > tx) {
718 _debug("hard-ACK'd packet %d not transmitted"
719 " (%d top)",
720 hard - 1, tx);
721 goto protocol_error;
722 }
723
724 if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY ||
725 call->state == RXRPC_CALL_SERVER_AWAIT_ACK) &&
726 hard > tx)
727 goto all_acked;
728
729 smp_rmb();
730 rxrpc_rotate_tx_window(call, hard - 1);
731 }
732
733 if (ack.nAcks > 0) {
734 if (hard - 1 + ack.nAcks > tx) {
735 _debug("soft-ACK'd packet %d+%d not"
736 " transmitted (%d top)",
737 hard - 1, ack.nAcks, tx);
738 goto protocol_error;
739 }
740
741 if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0)
742 goto protocol_error;
743 }
744 goto discard;
745
746 /* complete ACK to process */
747 case RXRPC_PACKET_TYPE_ACKALL:
748 goto all_acked;
749
750 /* abort and busy are handled elsewhere */
751 case RXRPC_PACKET_TYPE_BUSY:
752 case RXRPC_PACKET_TYPE_ABORT:
753 BUG();
754
755 /* connection level events - also handled elsewhere */
756 case RXRPC_PACKET_TYPE_CHALLENGE:
757 case RXRPC_PACKET_TYPE_RESPONSE:
758 case RXRPC_PACKET_TYPE_DEBUG:
759 BUG();
760 }
761
762 /* if we've had a hard ACK that covers all the packets we've sent, then
763 * that ends that phase of the operation */
764 all_acked:
765 write_lock_bh(&call->state_lock);
766 _debug("ack all %d", call->state);
767
768 switch (call->state) {
769 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
770 call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
771 break;
772 case RXRPC_CALL_SERVER_AWAIT_ACK:
773 _debug("srv complete");
774 call->state = RXRPC_CALL_COMPLETE;
775 post_ACK = true;
776 break;
777 case RXRPC_CALL_CLIENT_SEND_REQUEST:
778 case RXRPC_CALL_SERVER_RECV_REQUEST:
779 goto protocol_error_unlock; /* can't occur yet */
780 default:
781 write_unlock_bh(&call->state_lock);
782 goto discard; /* assume packet left over from earlier phase */
783 }
784
785 write_unlock_bh(&call->state_lock);
786
787 /* if all the packets we sent are hard-ACK'd, then we can discard
788 * whatever we've got left */
789 _debug("clear Tx %d",
790 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
791
792 del_timer_sync(&call->resend_timer);
793 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
794 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
795
796 if (call->acks_window)
797 rxrpc_zap_tx_window(call);
798
799 if (post_ACK) {
800 /* post the final ACK message for userspace to pick up */
801 _debug("post ACK");
802 skb->mark = RXRPC_SKB_MARK_FINAL_ACK;
803 sp->call = call;
804 rxrpc_get_call(call);
805 spin_lock_bh(&call->lock);
806 if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
807 BUG();
808 spin_unlock_bh(&call->lock);
809 goto process_further;
810 }
811
812 discard:
813 rxrpc_free_skb(skb);
814 goto process_further;
815
816 protocol_error_unlock:
817 write_unlock_bh(&call->state_lock);
818 protocol_error:
819 rxrpc_free_skb(skb);
820 _leave(" = -EPROTO");
821 return -EPROTO;
822 }
823
824 /*
825 * post a message to the socket Rx queue for recvmsg() to pick up
826 */
rxrpc_post_message(struct rxrpc_call * call,u32 mark,u32 error,bool fatal)827 static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error,
828 bool fatal)
829 {
830 struct rxrpc_skb_priv *sp;
831 struct sk_buff *skb;
832 int ret;
833
834 _enter("{%d,%lx},%u,%u,%d",
835 call->debug_id, call->flags, mark, error, fatal);
836
837 /* remove timers and things for fatal messages */
838 if (fatal) {
839 del_timer_sync(&call->resend_timer);
840 del_timer_sync(&call->ack_timer);
841 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
842 }
843
844 if (mark != RXRPC_SKB_MARK_NEW_CALL &&
845 !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
846 _leave("[no userid]");
847 return 0;
848 }
849
850 if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
851 skb = alloc_skb(0, GFP_NOFS);
852 if (!skb)
853 return -ENOMEM;
854
855 rxrpc_new_skb(skb);
856
857 skb->mark = mark;
858
859 sp = rxrpc_skb(skb);
860 memset(sp, 0, sizeof(*sp));
861 sp->error = error;
862 sp->call = call;
863 rxrpc_get_call(call);
864
865 spin_lock_bh(&call->lock);
866 ret = rxrpc_queue_rcv_skb(call, skb, true, fatal);
867 spin_unlock_bh(&call->lock);
868 BUG_ON(ret < 0);
869 }
870
871 return 0;
872 }
873
874 /*
875 * handle background processing of incoming call packets and ACK / abort
876 * generation
877 */
rxrpc_process_call(struct work_struct * work)878 void rxrpc_process_call(struct work_struct *work)
879 {
880 struct rxrpc_call *call =
881 container_of(work, struct rxrpc_call, processor);
882 struct rxrpc_ackpacket ack;
883 struct rxrpc_ackinfo ackinfo;
884 struct rxrpc_header hdr;
885 struct msghdr msg;
886 struct kvec iov[5];
887 unsigned long bits;
888 __be32 data, pad;
889 size_t len;
890 int genbit, loop, nbit, ioc, ret, mtu;
891 u32 abort_code = RX_PROTOCOL_ERROR;
892 u8 *acks = NULL;
893
894 //printk("\n--------------------\n");
895 _enter("{%d,%s,%lx} [%lu]",
896 call->debug_id, rxrpc_call_states[call->state], call->events,
897 (jiffies - call->creation_jif) / (HZ / 10));
898
899 if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) {
900 _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX");
901 return;
902 }
903
904 /* there's a good chance we're going to have to send a message, so set
905 * one up in advance */
906 msg.msg_name = &call->conn->trans->peer->srx.transport.sin;
907 msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin);
908 msg.msg_control = NULL;
909 msg.msg_controllen = 0;
910 msg.msg_flags = 0;
911
912 hdr.epoch = call->conn->epoch;
913 hdr.cid = call->cid;
914 hdr.callNumber = call->call_id;
915 hdr.seq = 0;
916 hdr.type = RXRPC_PACKET_TYPE_ACK;
917 hdr.flags = call->conn->out_clientflag;
918 hdr.userStatus = 0;
919 hdr.securityIndex = call->conn->security_ix;
920 hdr._rsvd = 0;
921 hdr.serviceId = call->conn->service_id;
922
923 memset(iov, 0, sizeof(iov));
924 iov[0].iov_base = &hdr;
925 iov[0].iov_len = sizeof(hdr);
926
927 /* deal with events of a final nature */
928 if (test_bit(RXRPC_CALL_RELEASE, &call->events)) {
929 rxrpc_release_call(call);
930 clear_bit(RXRPC_CALL_RELEASE, &call->events);
931 }
932
933 if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) {
934 int error;
935
936 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
937 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
938 clear_bit(RXRPC_CALL_ABORT, &call->events);
939
940 error = call->conn->trans->peer->net_error;
941 _debug("post net error %d", error);
942
943 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR,
944 error, true) < 0)
945 goto no_mem;
946 clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
947 goto kill_ACKs;
948 }
949
950 if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) {
951 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
952
953 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
954 clear_bit(RXRPC_CALL_ABORT, &call->events);
955
956 _debug("post conn abort");
957
958 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
959 call->conn->error, true) < 0)
960 goto no_mem;
961 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
962 goto kill_ACKs;
963 }
964
965 if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) {
966 hdr.type = RXRPC_PACKET_TYPE_BUSY;
967 genbit = RXRPC_CALL_REJECT_BUSY;
968 goto send_message;
969 }
970
971 if (test_bit(RXRPC_CALL_ABORT, &call->events)) {
972 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
973
974 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
975 ECONNABORTED, true) < 0)
976 goto no_mem;
977 hdr.type = RXRPC_PACKET_TYPE_ABORT;
978 data = htonl(call->abort_code);
979 iov[1].iov_base = &data;
980 iov[1].iov_len = sizeof(data);
981 genbit = RXRPC_CALL_ABORT;
982 goto send_message;
983 }
984
985 if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) {
986 genbit = RXRPC_CALL_ACK_FINAL;
987
988 ack.bufferSpace = htons(8);
989 ack.maxSkew = 0;
990 ack.serial = 0;
991 ack.reason = RXRPC_ACK_IDLE;
992 ack.nAcks = 0;
993 call->ackr_reason = 0;
994
995 spin_lock_bh(&call->lock);
996 ack.serial = call->ackr_serial;
997 ack.previousPacket = call->ackr_prev_seq;
998 ack.firstPacket = htonl(call->rx_data_eaten + 1);
999 spin_unlock_bh(&call->lock);
1000
1001 pad = 0;
1002
1003 iov[1].iov_base = &ack;
1004 iov[1].iov_len = sizeof(ack);
1005 iov[2].iov_base = &pad;
1006 iov[2].iov_len = 3;
1007 iov[3].iov_base = &ackinfo;
1008 iov[3].iov_len = sizeof(ackinfo);
1009 goto send_ACK;
1010 }
1011
1012 if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) |
1013 (1 << RXRPC_CALL_RCVD_ABORT))
1014 ) {
1015 u32 mark;
1016
1017 if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events))
1018 mark = RXRPC_SKB_MARK_REMOTE_ABORT;
1019 else
1020 mark = RXRPC_SKB_MARK_BUSY;
1021
1022 _debug("post abort/busy");
1023 rxrpc_clear_tx_window(call);
1024 if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0)
1025 goto no_mem;
1026
1027 clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
1028 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
1029 goto kill_ACKs;
1030 }
1031
1032 if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) {
1033 _debug("do implicit ackall");
1034 rxrpc_clear_tx_window(call);
1035 }
1036
1037 if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) {
1038 write_lock_bh(&call->state_lock);
1039 if (call->state <= RXRPC_CALL_COMPLETE) {
1040 call->state = RXRPC_CALL_LOCALLY_ABORTED;
1041 call->abort_code = RX_CALL_TIMEOUT;
1042 set_bit(RXRPC_CALL_ABORT, &call->events);
1043 }
1044 write_unlock_bh(&call->state_lock);
1045
1046 _debug("post timeout");
1047 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
1048 ETIME, true) < 0)
1049 goto no_mem;
1050
1051 clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
1052 goto kill_ACKs;
1053 }
1054
1055 /* deal with assorted inbound messages */
1056 if (!skb_queue_empty(&call->rx_queue)) {
1057 switch (rxrpc_process_rx_queue(call, &abort_code)) {
1058 case 0:
1059 case -EAGAIN:
1060 break;
1061 case -ENOMEM:
1062 goto no_mem;
1063 case -EKEYEXPIRED:
1064 case -EKEYREJECTED:
1065 case -EPROTO:
1066 rxrpc_abort_call(call, abort_code);
1067 goto kill_ACKs;
1068 }
1069 }
1070
1071 /* handle resending */
1072 if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
1073 rxrpc_resend_timer(call);
1074 if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events))
1075 rxrpc_resend(call);
1076
1077 /* consider sending an ordinary ACK */
1078 if (test_bit(RXRPC_CALL_ACK, &call->events)) {
1079 _debug("send ACK: window: %d - %d { %lx }",
1080 call->rx_data_eaten, call->ackr_win_top,
1081 call->ackr_window[0]);
1082
1083 if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST &&
1084 call->ackr_reason != RXRPC_ACK_PING_RESPONSE) {
1085 /* ACK by sending reply DATA packet in this state */
1086 clear_bit(RXRPC_CALL_ACK, &call->events);
1087 goto maybe_reschedule;
1088 }
1089
1090 genbit = RXRPC_CALL_ACK;
1091
1092 acks = kzalloc(call->ackr_win_top - call->rx_data_eaten,
1093 GFP_NOFS);
1094 if (!acks)
1095 goto no_mem;
1096
1097 //hdr.flags = RXRPC_SLOW_START_OK;
1098 ack.bufferSpace = htons(8);
1099 ack.maxSkew = 0;
1100 ack.serial = 0;
1101 ack.reason = 0;
1102
1103 spin_lock_bh(&call->lock);
1104 ack.reason = call->ackr_reason;
1105 ack.serial = call->ackr_serial;
1106 ack.previousPacket = call->ackr_prev_seq;
1107 ack.firstPacket = htonl(call->rx_data_eaten + 1);
1108
1109 ack.nAcks = 0;
1110 for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) {
1111 nbit = loop * BITS_PER_LONG;
1112 for (bits = call->ackr_window[loop]; bits; bits >>= 1
1113 ) {
1114 _debug("- l=%d n=%d b=%lx", loop, nbit, bits);
1115 if (bits & 1) {
1116 acks[nbit] = RXRPC_ACK_TYPE_ACK;
1117 ack.nAcks = nbit + 1;
1118 }
1119 nbit++;
1120 }
1121 }
1122 call->ackr_reason = 0;
1123 spin_unlock_bh(&call->lock);
1124
1125 pad = 0;
1126
1127 iov[1].iov_base = &ack;
1128 iov[1].iov_len = sizeof(ack);
1129 iov[2].iov_base = acks;
1130 iov[2].iov_len = ack.nAcks;
1131 iov[3].iov_base = &pad;
1132 iov[3].iov_len = 3;
1133 iov[4].iov_base = &ackinfo;
1134 iov[4].iov_len = sizeof(ackinfo);
1135
1136 switch (ack.reason) {
1137 case RXRPC_ACK_REQUESTED:
1138 case RXRPC_ACK_DUPLICATE:
1139 case RXRPC_ACK_OUT_OF_SEQUENCE:
1140 case RXRPC_ACK_EXCEEDS_WINDOW:
1141 case RXRPC_ACK_NOSPACE:
1142 case RXRPC_ACK_PING:
1143 case RXRPC_ACK_PING_RESPONSE:
1144 goto send_ACK_with_skew;
1145 case RXRPC_ACK_DELAY:
1146 case RXRPC_ACK_IDLE:
1147 goto send_ACK;
1148 }
1149 }
1150
1151 /* handle completion of security negotiations on an incoming
1152 * connection */
1153 if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) {
1154 _debug("secured");
1155 spin_lock_bh(&call->lock);
1156
1157 if (call->state == RXRPC_CALL_SERVER_SECURING) {
1158 _debug("securing");
1159 write_lock(&call->conn->lock);
1160 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1161 !test_bit(RXRPC_CALL_RELEASE, &call->events)) {
1162 _debug("not released");
1163 call->state = RXRPC_CALL_SERVER_ACCEPTING;
1164 list_move_tail(&call->accept_link,
1165 &call->socket->acceptq);
1166 }
1167 write_unlock(&call->conn->lock);
1168 read_lock(&call->state_lock);
1169 if (call->state < RXRPC_CALL_COMPLETE)
1170 set_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1171 read_unlock(&call->state_lock);
1172 }
1173
1174 spin_unlock_bh(&call->lock);
1175 if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events))
1176 goto maybe_reschedule;
1177 }
1178
1179 /* post a notification of an acceptable connection to the app */
1180 if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) {
1181 _debug("post accept");
1182 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL,
1183 0, false) < 0)
1184 goto no_mem;
1185 clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1186 goto maybe_reschedule;
1187 }
1188
1189 /* handle incoming call acceptance */
1190 if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) {
1191 _debug("accepted");
1192 ASSERTCMP(call->rx_data_post, ==, 0);
1193 call->rx_data_post = 1;
1194 read_lock_bh(&call->state_lock);
1195 if (call->state < RXRPC_CALL_COMPLETE)
1196 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
1197 read_unlock_bh(&call->state_lock);
1198 }
1199
1200 /* drain the out of sequence received packet queue into the packet Rx
1201 * queue */
1202 if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) {
1203 while (call->rx_data_post == call->rx_first_oos)
1204 if (rxrpc_drain_rx_oos_queue(call) < 0)
1205 break;
1206 goto maybe_reschedule;
1207 }
1208
1209 /* other events may have been raised since we started checking */
1210 goto maybe_reschedule;
1211
1212 send_ACK_with_skew:
1213 ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) -
1214 ntohl(ack.serial));
1215 send_ACK:
1216 mtu = call->conn->trans->peer->if_mtu;
1217 mtu -= call->conn->trans->peer->hdrsize;
1218 ackinfo.maxMTU = htonl(mtu);
1219 ackinfo.rwind = htonl(rxrpc_rx_window_size);
1220
1221 /* permit the peer to send us jumbo packets if it wants to */
1222 ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
1223 ackinfo.jumbo_max = htonl(rxrpc_rx_jumbo_max);
1224
1225 hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1226 _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
1227 ntohl(hdr.serial),
1228 ntohs(ack.maxSkew),
1229 ntohl(ack.firstPacket),
1230 ntohl(ack.previousPacket),
1231 ntohl(ack.serial),
1232 rxrpc_acks(ack.reason),
1233 ack.nAcks);
1234
1235 del_timer_sync(&call->ack_timer);
1236 if (ack.nAcks > 0)
1237 set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags);
1238 goto send_message_2;
1239
1240 send_message:
1241 _debug("send message");
1242
1243 hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1244 _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial));
1245 send_message_2:
1246
1247 len = iov[0].iov_len;
1248 ioc = 1;
1249 if (iov[4].iov_len) {
1250 ioc = 5;
1251 len += iov[4].iov_len;
1252 len += iov[3].iov_len;
1253 len += iov[2].iov_len;
1254 len += iov[1].iov_len;
1255 } else if (iov[3].iov_len) {
1256 ioc = 4;
1257 len += iov[3].iov_len;
1258 len += iov[2].iov_len;
1259 len += iov[1].iov_len;
1260 } else if (iov[2].iov_len) {
1261 ioc = 3;
1262 len += iov[2].iov_len;
1263 len += iov[1].iov_len;
1264 } else if (iov[1].iov_len) {
1265 ioc = 2;
1266 len += iov[1].iov_len;
1267 }
1268
1269 ret = kernel_sendmsg(call->conn->trans->local->socket,
1270 &msg, iov, ioc, len);
1271 if (ret < 0) {
1272 _debug("sendmsg failed: %d", ret);
1273 read_lock_bh(&call->state_lock);
1274 if (call->state < RXRPC_CALL_DEAD)
1275 rxrpc_queue_call(call);
1276 read_unlock_bh(&call->state_lock);
1277 goto error;
1278 }
1279
1280 switch (genbit) {
1281 case RXRPC_CALL_ABORT:
1282 clear_bit(genbit, &call->events);
1283 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
1284 goto kill_ACKs;
1285
1286 case RXRPC_CALL_ACK_FINAL:
1287 write_lock_bh(&call->state_lock);
1288 if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK)
1289 call->state = RXRPC_CALL_COMPLETE;
1290 write_unlock_bh(&call->state_lock);
1291 goto kill_ACKs;
1292
1293 default:
1294 clear_bit(genbit, &call->events);
1295 switch (call->state) {
1296 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
1297 case RXRPC_CALL_CLIENT_RECV_REPLY:
1298 case RXRPC_CALL_SERVER_RECV_REQUEST:
1299 case RXRPC_CALL_SERVER_ACK_REQUEST:
1300 _debug("start ACK timer");
1301 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY,
1302 call->ackr_serial, false);
1303 default:
1304 break;
1305 }
1306 goto maybe_reschedule;
1307 }
1308
1309 kill_ACKs:
1310 del_timer_sync(&call->ack_timer);
1311 if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events))
1312 rxrpc_put_call(call);
1313 clear_bit(RXRPC_CALL_ACK, &call->events);
1314
1315 maybe_reschedule:
1316 if (call->events || !skb_queue_empty(&call->rx_queue)) {
1317 read_lock_bh(&call->state_lock);
1318 if (call->state < RXRPC_CALL_DEAD)
1319 rxrpc_queue_call(call);
1320 read_unlock_bh(&call->state_lock);
1321 }
1322
1323 /* don't leave aborted connections on the accept queue */
1324 if (call->state >= RXRPC_CALL_COMPLETE &&
1325 !list_empty(&call->accept_link)) {
1326 _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }",
1327 call, call->events, call->flags,
1328 ntohl(call->conn->cid));
1329
1330 read_lock_bh(&call->state_lock);
1331 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1332 !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
1333 rxrpc_queue_call(call);
1334 read_unlock_bh(&call->state_lock);
1335 }
1336
1337 error:
1338 clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags);
1339 kfree(acks);
1340
1341 /* because we don't want two CPUs both processing the work item for one
1342 * call at the same time, we use a flag to note when it's busy; however
1343 * this means there's a race between clearing the flag and setting the
1344 * work pending bit and the work item being processed again */
1345 if (call->events && !work_pending(&call->processor)) {
1346 _debug("jumpstart %x", ntohl(call->conn->cid));
1347 rxrpc_queue_call(call);
1348 }
1349
1350 _leave("");
1351 return;
1352
1353 no_mem:
1354 _debug("out of memory");
1355 goto maybe_reschedule;
1356 }
1357