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