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