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[AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / rxrpc / ar-ack.c
blobfc07a926df563b215e76259861005422810fb5b4
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/udp.h>
17 #include <net/sock.h>
18 #include <net/af_rxrpc.h>
19 #include "ar-internal.h"
20
21 static unsigned rxrpc_ack_defer = 1;
22
23 static const char *rxrpc_acks[] = {
24 "---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY", "IDL",
25 "-?-"
26 };
27
28 static const s8 rxrpc_ack_priority[] = {
29 [0] = 0,
30 [RXRPC_ACK_DELAY] = 1,
31 [RXRPC_ACK_REQUESTED] = 2,
32 [RXRPC_ACK_IDLE] = 3,
33 [RXRPC_ACK_PING_RESPONSE] = 4,
34 [RXRPC_ACK_DUPLICATE] = 5,
35 [RXRPC_ACK_OUT_OF_SEQUENCE] = 6,
36 [RXRPC_ACK_EXCEEDS_WINDOW] = 7,
37 [RXRPC_ACK_NOSPACE] = 8,
38 };
39
40 /*
41 * propose an ACK be sent
42 */
43 void __rxrpc_propose_ACK(struct rxrpc_call *call, uint8_t ack_reason,
44 __be32 serial, bool immediate)
45 {
46 unsigned long expiry;
47 s8 prior = rxrpc_ack_priority[ack_reason];
48
49 ASSERTCMP(prior, >, 0);
50
51 _enter("{%d},%s,%%%x,%u",
52 call->debug_id, rxrpc_acks[ack_reason], ntohl(serial),
53 immediate);
54
55 if (prior < rxrpc_ack_priority[call->ackr_reason]) {
56 if (immediate)
57 goto cancel_timer;
58 return;
59 }
60
61 /* update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial
62 * numbers */
63 if (prior == rxrpc_ack_priority[call->ackr_reason]) {
64 if (prior <= 4)
65 call->ackr_serial = serial;
66 if (immediate)
67 goto cancel_timer;
68 return;
69 }
70
71 call->ackr_reason = ack_reason;
72 call->ackr_serial = serial;
73
74 switch (ack_reason) {
75 case RXRPC_ACK_DELAY:
76 _debug("run delay timer");
77 call->ack_timer.expires = jiffies + rxrpc_ack_timeout * HZ;
78 add_timer(&call->ack_timer);
79 return;
80
81 case RXRPC_ACK_IDLE:
82 if (!immediate) {
83 _debug("run defer timer");
84 expiry = 1;
85 goto run_timer;
86 }
87 goto cancel_timer;
88
89 case RXRPC_ACK_REQUESTED:
90 if (!rxrpc_ack_defer)
91 goto cancel_timer;
92 if (!immediate || serial == cpu_to_be32(1)) {
93 _debug("run defer timer");
94 expiry = rxrpc_ack_defer;
95 goto run_timer;
96 }
97
98 default:
99 _debug("immediate ACK");
100 goto cancel_timer;
101 }
102
103 run_timer:
104 expiry += jiffies;
105 if (!timer_pending(&call->ack_timer) ||
106 time_after(call->ack_timer.expires, expiry))
107 mod_timer(&call->ack_timer, expiry);
108 return;
109
110 cancel_timer:
111 _debug("cancel timer %%%u", ntohl(serial));
112 try_to_del_timer_sync(&call->ack_timer);
113 read_lock_bh(&call->state_lock);
114 if (call->state <= RXRPC_CALL_COMPLETE &&
115 !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
116 rxrpc_queue_call(call);
117 read_unlock_bh(&call->state_lock);
118 }
119
120 /*
121 * propose an ACK be sent, locking the call structure
122 */
123 void rxrpc_propose_ACK(struct rxrpc_call *call, uint8_t ack_reason,
124 __be32 serial, bool immediate)
125 {
126 s8 prior = rxrpc_ack_priority[ack_reason];
127
128 if (prior > rxrpc_ack_priority[call->ackr_reason]) {
129 spin_lock_bh(&call->lock);
130 __rxrpc_propose_ACK(call, ack_reason, serial, immediate);
131 spin_unlock_bh(&call->lock);
132 }
133 }
134
135 /*
136 * set the resend timer
137 */
138 static void rxrpc_set_resend(struct rxrpc_call *call, u8 resend,
139 unsigned long resend_at)
140 {
141 read_lock_bh(&call->state_lock);
142 if (call->state >= RXRPC_CALL_COMPLETE)
143 resend = 0;
144
145 if (resend & 1) {
146 _debug("SET RESEND");
147 set_bit(RXRPC_CALL_RESEND, &call->events);
148 }
149
150 if (resend & 2) {
151 _debug("MODIFY RESEND TIMER");
152 set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
153 mod_timer(&call->resend_timer, resend_at);
154 } else {
155 _debug("KILL RESEND TIMER");
156 del_timer_sync(&call->resend_timer);
157 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
158 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
159 }
160 read_unlock_bh(&call->state_lock);
161 }
162
163 /*
164 * resend packets
165 */
166 static void rxrpc_resend(struct rxrpc_call *call)
167 {
168 struct rxrpc_skb_priv *sp;
169 struct rxrpc_header *hdr;
170 struct sk_buff *txb;
171 unsigned long *p_txb, resend_at;
172 int loop, stop;
173 u8 resend;
174
175 _enter("{%d,%d,%d,%d},",
176 call->acks_hard, call->acks_unacked,
177 atomic_read(&call->sequence),
178 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
179
180 stop = 0;
181 resend = 0;
182 resend_at = 0;
183
184 for (loop = call->acks_tail;
185 loop != call->acks_head || stop;
186 loop = (loop + 1) & (call->acks_winsz - 1)
187 ) {
188 p_txb = call->acks_window + loop;
189 smp_read_barrier_depends();
190 if (*p_txb & 1)
191 continue;
192
193 txb = (struct sk_buff *) *p_txb;
194 sp = rxrpc_skb(txb);
195
196 if (sp->need_resend) {
197 sp->need_resend = 0;
198
199 /* each Tx packet has a new serial number */
200 sp->hdr.serial =
201 htonl(atomic_inc_return(&call->conn->serial));
202
203 hdr = (struct rxrpc_header *) txb->head;
204 hdr->serial = sp->hdr.serial;
205
206 _proto("Tx DATA %%%u { #%d }",
207 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
208 if (rxrpc_send_packet(call->conn->trans, txb) < 0) {
209 stop = 0;
210 sp->resend_at = jiffies + 3;
211 } else {
212 sp->resend_at =
213 jiffies + rxrpc_resend_timeout * HZ;
214 }
215 }
216
217 if (time_after_eq(jiffies + 1, sp->resend_at)) {
218 sp->need_resend = 1;
219 resend |= 1;
220 } else if (resend & 2) {
221 if (time_before(sp->resend_at, resend_at))
222 resend_at = sp->resend_at;
223 } else {
224 resend_at = sp->resend_at;
225 resend |= 2;
226 }
227 }
228
229 rxrpc_set_resend(call, resend, resend_at);
230 _leave("");
231 }
232
233 /*
234 * handle resend timer expiry
235 */
236 static void rxrpc_resend_timer(struct rxrpc_call *call)
237 {
238 struct rxrpc_skb_priv *sp;
239 struct sk_buff *txb;
240 unsigned long *p_txb, resend_at;
241 int loop;
242 u8 resend;
243
244 _enter("%d,%d,%d",
245 call->acks_tail, call->acks_unacked, call->acks_head);
246
247 resend = 0;
248 resend_at = 0;
249
250 for (loop = call->acks_unacked;
251 loop != call->acks_head;
252 loop = (loop + 1) & (call->acks_winsz - 1)
253 ) {
254 p_txb = call->acks_window + loop;
255 smp_read_barrier_depends();
256 txb = (struct sk_buff *) (*p_txb & ~1);
257 sp = rxrpc_skb(txb);
258
259 ASSERT(!(*p_txb & 1));
260
261 if (sp->need_resend) {
262 ;
263 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
264 sp->need_resend = 1;
265 resend |= 1;
266 } else if (resend & 2) {
267 if (time_before(sp->resend_at, resend_at))
268 resend_at = sp->resend_at;
269 } else {
270 resend_at = sp->resend_at;
271 resend |= 2;
272 }
273 }
274
275 rxrpc_set_resend(call, resend, resend_at);
276 _leave("");
277 }
278
279 /*
280 * process soft ACKs of our transmitted packets
281 * - these indicate packets the peer has or has not received, but hasn't yet
282 * given to the consumer, and so can still be discarded and re-requested
283 */
284 static int rxrpc_process_soft_ACKs(struct rxrpc_call *call,
285 struct rxrpc_ackpacket *ack,
286 struct sk_buff *skb)
287 {
288 struct rxrpc_skb_priv *sp;
289 struct sk_buff *txb;
290 unsigned long *p_txb, resend_at;
291 int loop;
292 u8 sacks[RXRPC_MAXACKS], resend;
293
294 _enter("{%d,%d},{%d},",
295 call->acks_hard,
296 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz),
297 ack->nAcks);
298
299 if (skb_copy_bits(skb, 0, sacks, ack->nAcks) < 0)
300 goto protocol_error;
301
302 resend = 0;
303 resend_at = 0;
304 for (loop = 0; loop < ack->nAcks; loop++) {
305 p_txb = call->acks_window;
306 p_txb += (call->acks_tail + loop) & (call->acks_winsz - 1);
307 smp_read_barrier_depends();
308 txb = (struct sk_buff *) (*p_txb & ~1);
309 sp = rxrpc_skb(txb);
310
311 switch (sacks[loop]) {
312 case RXRPC_ACK_TYPE_ACK:
313 sp->need_resend = 0;
314 *p_txb |= 1;
315 break;
316 case RXRPC_ACK_TYPE_NACK:
317 sp->need_resend = 1;
318 *p_txb &= ~1;
319 resend = 1;
320 break;
321 default:
322 _debug("Unsupported ACK type %d", sacks[loop]);
323 goto protocol_error;
324 }
325 }
326
327 smp_mb();
328 call->acks_unacked = (call->acks_tail + loop) & (call->acks_winsz - 1);
329
330 /* anything not explicitly ACK'd is implicitly NACK'd, but may just not
331 * have been received or processed yet by the far end */
332 for (loop = call->acks_unacked;
333 loop != call->acks_head;
334 loop = (loop + 1) & (call->acks_winsz - 1)
335 ) {
336 p_txb = call->acks_window + loop;
337 smp_read_barrier_depends();
338 txb = (struct sk_buff *) (*p_txb & ~1);
339 sp = rxrpc_skb(txb);
340
341 if (*p_txb & 1) {
342 /* packet must have been discarded */
343 sp->need_resend = 1;
344 *p_txb &= ~1;
345 resend |= 1;
346 } else if (sp->need_resend) {
347 ;
348 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
349 sp->need_resend = 1;
350 resend |= 1;
351 } else if (resend & 2) {
352 if (time_before(sp->resend_at, resend_at))
353 resend_at = sp->resend_at;
354 } else {
355 resend_at = sp->resend_at;
356 resend |= 2;
357 }
358 }
359
360 rxrpc_set_resend(call, resend, resend_at);
361 _leave(" = 0");
362 return 0;
363
364 protocol_error:
365 _leave(" = -EPROTO");
366 return -EPROTO;
367 }
368
369 /*
370 * discard hard-ACK'd packets from the Tx window
371 */
372 static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard)
373 {
374 struct rxrpc_skb_priv *sp;
375 unsigned long _skb;
376 int tail = call->acks_tail, old_tail;
377 int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz);
378
379 _enter("{%u,%u},%u", call->acks_hard, win, hard);
380
381 ASSERTCMP(hard - call->acks_hard, <=, win);
382
383 while (call->acks_hard < hard) {
384 smp_read_barrier_depends();
385 _skb = call->acks_window[tail] & ~1;
386 sp = rxrpc_skb((struct sk_buff *) _skb);
387 rxrpc_free_skb((struct sk_buff *) _skb);
388 old_tail = tail;
389 tail = (tail + 1) & (call->acks_winsz - 1);
390 call->acks_tail = tail;
391 if (call->acks_unacked == old_tail)
392 call->acks_unacked = tail;
393 call->acks_hard++;
394 }
395
396 wake_up(&call->tx_waitq);
397 }
398
399 /*
400 * clear the Tx window in the event of a failure
401 */
402 static void rxrpc_clear_tx_window(struct rxrpc_call *call)
403 {
404 rxrpc_rotate_tx_window(call, atomic_read(&call->sequence));
405 }
406
407 /*
408 * drain the out of sequence received packet queue into the packet Rx queue
409 */
410 static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call)
411 {
412 struct rxrpc_skb_priv *sp;
413 struct sk_buff *skb;
414 bool terminal;
415 int ret;
416
417 _enter("{%d,%d}", call->rx_data_post, call->rx_first_oos);
418
419 spin_lock_bh(&call->lock);
420
421 ret = -ECONNRESET;
422 if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
423 goto socket_unavailable;
424
425 skb = skb_dequeue(&call->rx_oos_queue);
426 if (skb) {
427 sp = rxrpc_skb(skb);
428
429 _debug("drain OOS packet %d [%d]",
430 ntohl(sp->hdr.seq), call->rx_first_oos);
431
432 if (ntohl(sp->hdr.seq) != call->rx_first_oos) {
433 skb_queue_head(&call->rx_oos_queue, skb);
434 call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq);
435 _debug("requeue %p {%u}", skb, call->rx_first_oos);
436 } else {
437 skb->mark = RXRPC_SKB_MARK_DATA;
438 terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
439 !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
440 ret = rxrpc_queue_rcv_skb(call, skb, true, terminal);
441 BUG_ON(ret < 0);
442 _debug("drain #%u", call->rx_data_post);
443 call->rx_data_post++;
444
445 /* find out what the next packet is */
446 skb = skb_peek(&call->rx_oos_queue);
447 if (skb)
448 call->rx_first_oos =
449 ntohl(rxrpc_skb(skb)->hdr.seq);
450 else
451 call->rx_first_oos = 0;
452 _debug("peek %p {%u}", skb, call->rx_first_oos);
453 }
454 }
455
456 ret = 0;
457 socket_unavailable:
458 spin_unlock_bh(&call->lock);
459 _leave(" = %d", ret);
460 return ret;
461 }
462
463 /*
464 * insert an out of sequence packet into the buffer
465 */
466 static void rxrpc_insert_oos_packet(struct rxrpc_call *call,
467 struct sk_buff *skb)
468 {
469 struct rxrpc_skb_priv *sp, *psp;
470 struct sk_buff *p;
471 u32 seq;
472
473 sp = rxrpc_skb(skb);
474 seq = ntohl(sp->hdr.seq);
475 _enter(",,{%u}", seq);
476
477 skb->destructor = rxrpc_packet_destructor;
478 ASSERTCMP(sp->call, ==, NULL);
479 sp->call = call;
480 rxrpc_get_call(call);
481
482 /* insert into the buffer in sequence order */
483 spin_lock_bh(&call->lock);
484
485 skb_queue_walk(&call->rx_oos_queue, p) {
486 psp = rxrpc_skb(p);
487 if (ntohl(psp->hdr.seq) > seq) {
488 _debug("insert oos #%u before #%u",
489 seq, ntohl(psp->hdr.seq));
490 skb_insert(p, skb, &call->rx_oos_queue);
491 goto inserted;
492 }
493 }
494
495 _debug("append oos #%u", seq);
496 skb_queue_tail(&call->rx_oos_queue, skb);
497 inserted:
498
499 /* we might now have a new front to the queue */
500 if (call->rx_first_oos == 0 || seq < call->rx_first_oos)
501 call->rx_first_oos = seq;
502
503 read_lock(&call->state_lock);
504 if (call->state < RXRPC_CALL_COMPLETE &&
505 call->rx_data_post == call->rx_first_oos) {
506 _debug("drain rx oos now");
507 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
508 }
509 read_unlock(&call->state_lock);
510
511 spin_unlock_bh(&call->lock);
512 _leave(" [stored #%u]", call->rx_first_oos);
513 }
514
515 /*
516 * clear the Tx window on final ACK reception
517 */
518 static void rxrpc_zap_tx_window(struct rxrpc_call *call)
519 {
520 struct rxrpc_skb_priv *sp;
521 struct sk_buff *skb;
522 unsigned long _skb, *acks_window;
523 uint8_t winsz = call->acks_winsz;
524 int tail;
525
526 acks_window = call->acks_window;
527 call->acks_window = NULL;
528
529 while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) {
530 tail = call->acks_tail;
531 smp_read_barrier_depends();
532 _skb = acks_window[tail] & ~1;
533 smp_mb();
534 call->acks_tail = (call->acks_tail + 1) & (winsz - 1);
535
536 skb = (struct sk_buff *) _skb;
537 sp = rxrpc_skb(skb);
538 _debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
539 rxrpc_free_skb(skb);
540 }
541
542 kfree(acks_window);
543 }
544
545 /*
546 * process packets in the reception queue
547 */
548 static int rxrpc_process_rx_queue(struct rxrpc_call *call,
549 u32 *_abort_code)
550 {
551 struct rxrpc_ackpacket ack;
552 struct rxrpc_skb_priv *sp;
553 struct sk_buff *skb;
554 bool post_ACK;
555 int latest;
556 u32 hard, tx;
557
558 _enter("");
559
560 process_further:
561 skb = skb_dequeue(&call->rx_queue);
562 if (!skb)
563 return -EAGAIN;
564
565 _net("deferred skb %p", skb);
566
567 sp = rxrpc_skb(skb);
568
569 _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state);
570
571 post_ACK = false;
572
573 switch (sp->hdr.type) {
574 /* data packets that wind up here have been received out of
575 * order, need security processing or are jumbo packets */
576 case RXRPC_PACKET_TYPE_DATA:
577 _proto("OOSQ DATA %%%u { #%u }",
578 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
579
580 /* secured packets must be verified and possibly decrypted */
581 if (rxrpc_verify_packet(call, skb, _abort_code) < 0)
582 goto protocol_error;
583
584 rxrpc_insert_oos_packet(call, skb);
585 goto process_further;
586
587 /* partial ACK to process */
588 case RXRPC_PACKET_TYPE_ACK:
589 if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) {
590 _debug("extraction failure");
591 goto protocol_error;
592 }
593 if (!skb_pull(skb, sizeof(ack)))
594 BUG();
595
596 latest = ntohl(sp->hdr.serial);
597 hard = ntohl(ack.firstPacket);
598 tx = atomic_read(&call->sequence);
599
600 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
601 latest,
602 ntohs(ack.maxSkew),
603 hard,
604 ntohl(ack.previousPacket),
605 ntohl(ack.serial),
606 rxrpc_acks[ack.reason],
607 ack.nAcks);
608
609 if (ack.reason == RXRPC_ACK_PING) {
610 _proto("Rx ACK %%%u PING Request", latest);
611 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
612 sp->hdr.serial, true);
613 }
614
615 /* discard any out-of-order or duplicate ACKs */
616 if (latest - call->acks_latest <= 0) {
617 _debug("discard ACK %d <= %d",
618 latest, call->acks_latest);
619 goto discard;
620 }
621 call->acks_latest = latest;
622
623 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
624 call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY &&
625 call->state != RXRPC_CALL_SERVER_SEND_REPLY &&
626 call->state != RXRPC_CALL_SERVER_AWAIT_ACK)
627 goto discard;
628
629 _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state);
630
631 if (hard > 0) {
632 if (hard - 1 > tx) {
633 _debug("hard-ACK'd packet %d not transmitted"
634 " (%d top)",
635 hard - 1, tx);
636 goto protocol_error;
637 }
638
639 if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY ||
640 call->state == RXRPC_CALL_SERVER_AWAIT_ACK) &&
641 hard > tx)
642 goto all_acked;
643
644 smp_rmb();
645 rxrpc_rotate_tx_window(call, hard - 1);
646 }
647
648 if (ack.nAcks > 0) {
649 if (hard - 1 + ack.nAcks > tx) {
650 _debug("soft-ACK'd packet %d+%d not"
651 " transmitted (%d top)",
652 hard - 1, ack.nAcks, tx);
653 goto protocol_error;
654 }
655
656 if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0)
657 goto protocol_error;
658 }
659 goto discard;
660
661 /* complete ACK to process */
662 case RXRPC_PACKET_TYPE_ACKALL:
663 goto all_acked;
664
665 /* abort and busy are handled elsewhere */
666 case RXRPC_PACKET_TYPE_BUSY:
667 case RXRPC_PACKET_TYPE_ABORT:
668 BUG();
669
670 /* connection level events - also handled elsewhere */
671 case RXRPC_PACKET_TYPE_CHALLENGE:
672 case RXRPC_PACKET_TYPE_RESPONSE:
673 case RXRPC_PACKET_TYPE_DEBUG:
674 BUG();
675 }
676
677 /* if we've had a hard ACK that covers all the packets we've sent, then
678 * that ends that phase of the operation */
679 all_acked:
680 write_lock_bh(&call->state_lock);
681 _debug("ack all %d", call->state);
682
683 switch (call->state) {
684 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
685 call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
686 break;
687 case RXRPC_CALL_SERVER_AWAIT_ACK:
688 _debug("srv complete");
689 call->state = RXRPC_CALL_COMPLETE;
690 post_ACK = true;
691 break;
692 case RXRPC_CALL_CLIENT_SEND_REQUEST:
693 case RXRPC_CALL_SERVER_RECV_REQUEST:
694 goto protocol_error_unlock; /* can't occur yet */
695 default:
696 write_unlock_bh(&call->state_lock);
697 goto discard; /* assume packet left over from earlier phase */
698 }
699
700 write_unlock_bh(&call->state_lock);
701
702 /* if all the packets we sent are hard-ACK'd, then we can discard
703 * whatever we've got left */
704 _debug("clear Tx %d",
705 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
706
707 del_timer_sync(&call->resend_timer);
708 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
709 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
710
711 if (call->acks_window)
712 rxrpc_zap_tx_window(call);
713
714 if (post_ACK) {
715 /* post the final ACK message for userspace to pick up */
716 _debug("post ACK");
717 skb->mark = RXRPC_SKB_MARK_FINAL_ACK;
718 sp->call = call;
719 rxrpc_get_call(call);
720 spin_lock_bh(&call->lock);
721 if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
722 BUG();
723 spin_unlock_bh(&call->lock);
724 goto process_further;
725 }
726
727 discard:
728 rxrpc_free_skb(skb);
729 goto process_further;
730
731 protocol_error_unlock:
732 write_unlock_bh(&call->state_lock);
733 protocol_error:
734 rxrpc_free_skb(skb);
735 _leave(" = -EPROTO");
736 return -EPROTO;
737 }
738
739 /*
740 * post a message to the socket Rx queue for recvmsg() to pick up
741 */
742 static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error,
743 bool fatal)
744 {
745 struct rxrpc_skb_priv *sp;
746 struct sk_buff *skb;
747 int ret;
748
749 _enter("{%d,%lx},%u,%u,%d",
750 call->debug_id, call->flags, mark, error, fatal);
751
752 /* remove timers and things for fatal messages */
753 if (fatal) {
754 del_timer_sync(&call->resend_timer);
755 del_timer_sync(&call->ack_timer);
756 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
757 }
758
759 if (mark != RXRPC_SKB_MARK_NEW_CALL &&
760 !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
761 _leave("[no userid]");
762 return 0;
763 }
764
765 if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
766 skb = alloc_skb(0, GFP_NOFS);
767 if (!skb)
768 return -ENOMEM;
769
770 rxrpc_new_skb(skb);
771
772 skb->mark = mark;
773
774 sp = rxrpc_skb(skb);
775 memset(sp, 0, sizeof(*sp));
776 sp->error = error;
777 sp->call = call;
778 rxrpc_get_call(call);
779
780 spin_lock_bh(&call->lock);
781 ret = rxrpc_queue_rcv_skb(call, skb, true, fatal);
782 spin_unlock_bh(&call->lock);
783 if (ret < 0)
784 BUG();
785 }
786
787 return 0;
788 }
789
790 /*
791 * handle background processing of incoming call packets and ACK / abort
792 * generation
793 */
794 void rxrpc_process_call(struct work_struct *work)
795 {
796 struct rxrpc_call *call =
797 container_of(work, struct rxrpc_call, processor);
798 struct rxrpc_ackpacket ack;
799 struct rxrpc_ackinfo ackinfo;
800 struct rxrpc_header hdr;
801 struct msghdr msg;
802 struct kvec iov[5];
803 unsigned long bits;
804 __be32 data;
805 size_t len;
806 int genbit, loop, nbit, ioc, ret;
807 u32 abort_code = RX_PROTOCOL_ERROR;
808 u8 *acks = NULL;
809
810 //printk("\n--------------------\n");
811 _enter("{%d,%s,%lx} [%lu]",
812 call->debug_id, rxrpc_call_states[call->state], call->events,
813 (jiffies - call->creation_jif) / (HZ / 10));
814
815 if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) {
816 _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX");
817 return;
818 }
819
820 /* there's a good chance we're going to have to send a message, so set
821 * one up in advance */
822 msg.msg_name = &call->conn->trans->peer->srx.transport.sin;
823 msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin);
824 msg.msg_control = NULL;
825 msg.msg_controllen = 0;
826 msg.msg_flags = 0;
827
828 hdr.epoch = call->conn->epoch;
829 hdr.cid = call->cid;
830 hdr.callNumber = call->call_id;
831 hdr.seq = 0;
832 hdr.type = RXRPC_PACKET_TYPE_ACK;
833 hdr.flags = call->conn->out_clientflag;
834 hdr.userStatus = 0;
835 hdr.securityIndex = call->conn->security_ix;
836 hdr._rsvd = 0;
837 hdr.serviceId = call->conn->service_id;
838
839 memset(iov, 0, sizeof(iov));
840 iov[0].iov_base = &hdr;
841 iov[0].iov_len = sizeof(hdr);
842
843 /* deal with events of a final nature */
844 if (test_bit(RXRPC_CALL_RELEASE, &call->events)) {
845 rxrpc_release_call(call);
846 clear_bit(RXRPC_CALL_RELEASE, &call->events);
847 }
848
849 if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) {
850 int error;
851
852 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
853 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
854 clear_bit(RXRPC_CALL_ABORT, &call->events);
855
856 error = call->conn->trans->peer->net_error;
857 _debug("post net error %d", error);
858
859 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR,
860 error, true) < 0)
861 goto no_mem;
862 clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
863 goto kill_ACKs;
864 }
865
866 if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) {
867 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
868
869 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
870 clear_bit(RXRPC_CALL_ABORT, &call->events);
871
872 _debug("post conn abort");
873
874 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
875 call->conn->error, true) < 0)
876 goto no_mem;
877 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
878 goto kill_ACKs;
879 }
880
881 if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) {
882 hdr.type = RXRPC_PACKET_TYPE_BUSY;
883 genbit = RXRPC_CALL_REJECT_BUSY;
884 goto send_message;
885 }
886
887 if (test_bit(RXRPC_CALL_ABORT, &call->events)) {
888 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
889
890 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
891 ECONNABORTED, true) < 0)
892 goto no_mem;
893 hdr.type = RXRPC_PACKET_TYPE_ABORT;
894 data = htonl(call->abort_code);
895 iov[1].iov_base = &data;
896 iov[1].iov_len = sizeof(data);
897 genbit = RXRPC_CALL_ABORT;
898 goto send_message;
899 }
900
901 if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) {
902 hdr.type = RXRPC_PACKET_TYPE_ACKALL;
903 genbit = RXRPC_CALL_ACK_FINAL;
904 goto send_message;
905 }
906
907 if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) |
908 (1 << RXRPC_CALL_RCVD_ABORT))
909 ) {
910 u32 mark;
911
912 if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events))
913 mark = RXRPC_SKB_MARK_REMOTE_ABORT;
914 else
915 mark = RXRPC_SKB_MARK_BUSY;
916
917 _debug("post abort/busy");
918 rxrpc_clear_tx_window(call);
919 if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0)
920 goto no_mem;
921
922 clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
923 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
924 goto kill_ACKs;
925 }
926
927 if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) {
928 _debug("do implicit ackall");
929 rxrpc_clear_tx_window(call);
930 }
931
932 if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) {
933 write_lock_bh(&call->state_lock);
934 if (call->state <= RXRPC_CALL_COMPLETE) {
935 call->state = RXRPC_CALL_LOCALLY_ABORTED;
936 call->abort_code = RX_CALL_TIMEOUT;
937 set_bit(RXRPC_CALL_ABORT, &call->events);
938 }
939 write_unlock_bh(&call->state_lock);
940
941 _debug("post timeout");
942 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
943 ETIME, true) < 0)
944 goto no_mem;
945
946 clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
947 goto kill_ACKs;
948 }
949
950 /* deal with assorted inbound messages */
951 if (!skb_queue_empty(&call->rx_queue)) {
952 switch (rxrpc_process_rx_queue(call, &abort_code)) {
953 case 0:
954 case -EAGAIN:
955 break;
956 case -ENOMEM:
957 goto no_mem;
958 case -EKEYEXPIRED:
959 case -EKEYREJECTED:
960 case -EPROTO:
961 rxrpc_abort_call(call, abort_code);
962 goto kill_ACKs;
963 }
964 }
965
966 /* handle resending */
967 if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
968 rxrpc_resend_timer(call);
969 if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events))
970 rxrpc_resend(call);
971
972 /* consider sending an ordinary ACK */
973 if (test_bit(RXRPC_CALL_ACK, &call->events)) {
974 __be32 pad;
975
976 _debug("send ACK: window: %d - %d { %lx }",
977 call->rx_data_eaten, call->ackr_win_top,
978 call->ackr_window[0]);
979
980 if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST &&
981 call->ackr_reason != RXRPC_ACK_PING_RESPONSE) {
982 /* ACK by sending reply DATA packet in this state */
983 clear_bit(RXRPC_CALL_ACK, &call->events);
984 goto maybe_reschedule;
985 }
986
987 genbit = RXRPC_CALL_ACK;
988
989 acks = kzalloc(call->ackr_win_top - call->rx_data_eaten,
990 GFP_NOFS);
991 if (!acks)
992 goto no_mem;
993
994 //hdr.flags = RXRPC_SLOW_START_OK;
995 ack.bufferSpace = htons(8);
996 ack.maxSkew = 0;
997 ack.serial = 0;
998 ack.reason = 0;
999
1000 ackinfo.rxMTU = htonl(5692);
1001 // ackinfo.rxMTU = htonl(call->conn->trans->peer->maxdata);
1002 ackinfo.maxMTU = htonl(call->conn->trans->peer->maxdata);
1003 ackinfo.rwind = htonl(32);
1004 ackinfo.jumbo_max = htonl(4);
1005
1006 spin_lock_bh(&call->lock);
1007 ack.reason = call->ackr_reason;
1008 ack.serial = call->ackr_serial;
1009 ack.previousPacket = call->ackr_prev_seq;
1010 ack.firstPacket = htonl(call->rx_data_eaten + 1);
1011
1012 ack.nAcks = 0;
1013 for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) {
1014 nbit = loop * BITS_PER_LONG;
1015 for (bits = call->ackr_window[loop]; bits; bits >>= 1
1016 ) {
1017 _debug("- l=%d n=%d b=%lx", loop, nbit, bits);
1018 if (bits & 1) {
1019 acks[nbit] = RXRPC_ACK_TYPE_ACK;
1020 ack.nAcks = nbit + 1;
1021 }
1022 nbit++;
1023 }
1024 }
1025 call->ackr_reason = 0;
1026 spin_unlock_bh(&call->lock);
1027
1028 pad = 0;
1029
1030 iov[1].iov_base = &ack;
1031 iov[1].iov_len = sizeof(ack);
1032 iov[2].iov_base = acks;
1033 iov[2].iov_len = ack.nAcks;
1034 iov[3].iov_base = &pad;
1035 iov[3].iov_len = 3;
1036 iov[4].iov_base = &ackinfo;
1037 iov[4].iov_len = sizeof(ackinfo);
1038
1039 switch (ack.reason) {
1040 case RXRPC_ACK_REQUESTED:
1041 case RXRPC_ACK_DUPLICATE:
1042 case RXRPC_ACK_OUT_OF_SEQUENCE:
1043 case RXRPC_ACK_EXCEEDS_WINDOW:
1044 case RXRPC_ACK_NOSPACE:
1045 case RXRPC_ACK_PING:
1046 case RXRPC_ACK_PING_RESPONSE:
1047 goto send_ACK_with_skew;
1048 case RXRPC_ACK_DELAY:
1049 case RXRPC_ACK_IDLE:
1050 goto send_ACK;
1051 }
1052 }
1053
1054 /* handle completion of security negotiations on an incoming
1055 * connection */
1056 if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) {
1057 _debug("secured");
1058 spin_lock_bh(&call->lock);
1059
1060 if (call->state == RXRPC_CALL_SERVER_SECURING) {
1061 _debug("securing");
1062 write_lock(&call->conn->lock);
1063 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1064 !test_bit(RXRPC_CALL_RELEASE, &call->events)) {
1065 _debug("not released");
1066 call->state = RXRPC_CALL_SERVER_ACCEPTING;
1067 list_move_tail(&call->accept_link,
1068 &call->socket->acceptq);
1069 }
1070 write_unlock(&call->conn->lock);
1071 read_lock(&call->state_lock);
1072 if (call->state < RXRPC_CALL_COMPLETE)
1073 set_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1074 read_unlock(&call->state_lock);
1075 }
1076
1077 spin_unlock_bh(&call->lock);
1078 if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events))
1079 goto maybe_reschedule;
1080 }
1081
1082 /* post a notification of an acceptable connection to the app */
1083 if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) {
1084 _debug("post accept");
1085 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL,
1086 0, false) < 0)
1087 goto no_mem;
1088 clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1089 goto maybe_reschedule;
1090 }
1091
1092 /* handle incoming call acceptance */
1093 if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) {
1094 _debug("accepted");
1095 ASSERTCMP(call->rx_data_post, ==, 0);
1096 call->rx_data_post = 1;
1097 read_lock_bh(&call->state_lock);
1098 if (call->state < RXRPC_CALL_COMPLETE)
1099 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
1100 read_unlock_bh(&call->state_lock);
1101 }
1102
1103 /* drain the out of sequence received packet queue into the packet Rx
1104 * queue */
1105 if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) {
1106 while (call->rx_data_post == call->rx_first_oos)
1107 if (rxrpc_drain_rx_oos_queue(call) < 0)
1108 break;
1109 goto maybe_reschedule;
1110 }
1111
1112 /* other events may have been raised since we started checking */
1113 goto maybe_reschedule;
1114
1115 send_ACK_with_skew:
1116 ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) -
1117 ntohl(ack.serial));
1118 send_ACK:
1119 hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1120 _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
1121 ntohl(hdr.serial),
1122 ntohs(ack.maxSkew),
1123 ntohl(ack.firstPacket),
1124 ntohl(ack.previousPacket),
1125 ntohl(ack.serial),
1126 rxrpc_acks[ack.reason],
1127 ack.nAcks);
1128
1129 del_timer_sync(&call->ack_timer);
1130 if (ack.nAcks > 0)
1131 set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags);
1132 goto send_message_2;
1133
1134 send_message:
1135 _debug("send message");
1136
1137 hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1138 _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial));
1139 send_message_2:
1140
1141 len = iov[0].iov_len;
1142 ioc = 1;
1143 if (iov[4].iov_len) {
1144 ioc = 5;
1145 len += iov[4].iov_len;
1146 len += iov[3].iov_len;
1147 len += iov[2].iov_len;
1148 len += iov[1].iov_len;
1149 } else if (iov[3].iov_len) {
1150 ioc = 4;
1151 len += iov[3].iov_len;
1152 len += iov[2].iov_len;
1153 len += iov[1].iov_len;
1154 } else if (iov[2].iov_len) {
1155 ioc = 3;
1156 len += iov[2].iov_len;
1157 len += iov[1].iov_len;
1158 } else if (iov[1].iov_len) {
1159 ioc = 2;
1160 len += iov[1].iov_len;
1161 }
1162
1163 ret = kernel_sendmsg(call->conn->trans->local->socket,
1164 &msg, iov, ioc, len);
1165 if (ret < 0) {
1166 _debug("sendmsg failed: %d", ret);
1167 read_lock_bh(&call->state_lock);
1168 if (call->state < RXRPC_CALL_DEAD)
1169 rxrpc_queue_call(call);
1170 read_unlock_bh(&call->state_lock);
1171 goto error;
1172 }
1173
1174 switch (genbit) {
1175 case RXRPC_CALL_ABORT:
1176 clear_bit(genbit, &call->events);
1177 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
1178 goto kill_ACKs;
1179
1180 case RXRPC_CALL_ACK_FINAL:
1181 write_lock_bh(&call->state_lock);
1182 if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK)
1183 call->state = RXRPC_CALL_COMPLETE;
1184 write_unlock_bh(&call->state_lock);
1185 goto kill_ACKs;
1186
1187 default:
1188 clear_bit(genbit, &call->events);
1189 switch (call->state) {
1190 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
1191 case RXRPC_CALL_CLIENT_RECV_REPLY:
1192 case RXRPC_CALL_SERVER_RECV_REQUEST:
1193 case RXRPC_CALL_SERVER_ACK_REQUEST:
1194 _debug("start ACK timer");
1195 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY,
1196 call->ackr_serial, false);
1197 default:
1198 break;
1199 }
1200 goto maybe_reschedule;
1201 }
1202
1203 kill_ACKs:
1204 del_timer_sync(&call->ack_timer);
1205 if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events))
1206 rxrpc_put_call(call);
1207 clear_bit(RXRPC_CALL_ACK, &call->events);
1208
1209 maybe_reschedule:
1210 if (call->events || !skb_queue_empty(&call->rx_queue)) {
1211 read_lock_bh(&call->state_lock);
1212 if (call->state < RXRPC_CALL_DEAD)
1213 rxrpc_queue_call(call);
1214 read_unlock_bh(&call->state_lock);
1215 }
1216
1217 /* don't leave aborted connections on the accept queue */
1218 if (call->state >= RXRPC_CALL_COMPLETE &&
1219 !list_empty(&call->accept_link)) {
1220 _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }",
1221 call, call->events, call->flags,
1222 ntohl(call->conn->cid));
1223
1224 read_lock_bh(&call->state_lock);
1225 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1226 !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
1227 rxrpc_queue_call(call);
1228 read_unlock_bh(&call->state_lock);
1229 }
1230
1231 error:
1232 clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags);
1233 kfree(acks);
1234
1235 /* because we don't want two CPUs both processing the work item for one
1236 * call at the same time, we use a flag to note when it's busy; however
1237 * this means there's a race between clearing the flag and setting the
1238 * work pending bit and the work item being processed again */
1239 if (call->events && !work_pending(&call->processor)) {
1240 _debug("jumpstart %x", ntohl(call->conn->cid));
1241 rxrpc_queue_call(call);
1242 }
1243
1244 _leave("");
1245 return;
1246
1247 no_mem:
1248 _debug("out of memory");
1249 goto maybe_reschedule;
1250 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree