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