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 21static unsigned rxrpc_ack_defer = 1; 22 23static const char *rxrpc_acks[] = { 24 "---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY", "IDL", 25 "-?-" 26}; 27 28static 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 */ 43void __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 103run_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 110cancel_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 */ 123void 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 */ 138static 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 */ 166static 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 */ 236static 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 */ 284static 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 364protocol_error: 365 _leave(" = -EPROTO"); 366 return -EPROTO; 367} 368 369/* 370 * discard hard-ACK'd packets from the Tx window 371 */ 372static 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 */ 402static 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 */ 410static 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; 457socket_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 */ 466static 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); 497inserted: 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 */ 518static 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 the extra information that may be appended to an ACK packet 547 */ 548static void rxrpc_extract_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 549 unsigned latest, int nAcks) 550{ 551 struct rxrpc_ackinfo ackinfo; 552 struct rxrpc_peer *peer; 553 unsigned mtu; 554 555 if (skb_copy_bits(skb, nAcks + 3, &ackinfo, sizeof(ackinfo)) < 0) { 556 _leave(" [no ackinfo]"); 557 return; 558 } 559 560 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 561 latest, 562 ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU), 563 ntohl(ackinfo.rwind), ntohl(ackinfo.jumbo_max)); 564 565 mtu = min(ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU)); 566 567 peer = call->conn->trans->peer; 568 if (mtu < peer->maxdata) { 569 spin_lock_bh(&peer->lock); 570 peer->maxdata = mtu; 571 peer->mtu = mtu + peer->hdrsize; 572 spin_unlock_bh(&peer->lock); 573 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 574 } 575} 576 577/* 578 * process packets in the reception queue 579 */ 580static int rxrpc_process_rx_queue(struct rxrpc_call *call, 581 u32 *_abort_code) 582{ 583 struct rxrpc_ackpacket ack; 584 struct rxrpc_skb_priv *sp; 585 struct sk_buff *skb; 586 bool post_ACK; 587 int latest; 588 u32 hard, tx; 589 590 _enter(""); 591 592process_further: 593 skb = skb_dequeue(&call->rx_queue); 594 if (!skb) 595 return -EAGAIN; 596 597 _net("deferred skb %p", skb); 598 599 sp = rxrpc_skb(skb); 600 601 _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state); 602 603 post_ACK = false; 604 605 switch (sp->hdr.type) { 606 /* data packets that wind up here have been received out of 607 * order, need security processing or are jumbo packets */ 608 case RXRPC_PACKET_TYPE_DATA: 609 _proto("OOSQ DATA %%%u { #%u }", 610 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq)); 611 612 /* secured packets must be verified and possibly decrypted */ 613 if (rxrpc_verify_packet(call, skb, _abort_code) < 0) 614 goto protocol_error; 615 616 rxrpc_insert_oos_packet(call, skb); 617 goto process_further; 618 619 /* partial ACK to process */ 620 case RXRPC_PACKET_TYPE_ACK: 621 if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) { 622 _debug("extraction failure"); 623 goto protocol_error; 624 } 625 if (!skb_pull(skb, sizeof(ack))) 626 BUG(); 627 628 latest = ntohl(sp->hdr.serial); 629 hard = ntohl(ack.firstPacket); 630 tx = atomic_read(&call->sequence); 631 632 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", 633 latest, 634 ntohs(ack.maxSkew), 635 hard, 636 ntohl(ack.previousPacket), 637 ntohl(ack.serial), 638 rxrpc_acks[ack.reason], 639 ack.nAcks); 640 641 rxrpc_extract_ackinfo(call, skb, latest, ack.nAcks); 642 643 if (ack.reason == RXRPC_ACK_PING) { 644 _proto("Rx ACK %%%u PING Request", latest); 645 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 646 sp->hdr.serial, true); 647 } 648 649 /* discard any out-of-order or duplicate ACKs */ 650 if (latest - call->acks_latest <= 0) { 651 _debug("discard ACK %d <= %d", 652 latest, call->acks_latest); 653 goto discard; 654 } 655 call->acks_latest = latest; 656 657 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST && 658 call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY && 659 call->state != RXRPC_CALL_SERVER_SEND_REPLY && 660 call->state != RXRPC_CALL_SERVER_AWAIT_ACK) 661 goto discard; 662 663 _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state); 664 665 if (hard > 0) { 666 if (hard - 1 > tx) { 667 _debug("hard-ACK'd packet %d not transmitted" 668 " (%d top)", 669 hard - 1, tx); 670 goto protocol_error; 671 } 672 673 if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY || 674 call->state == RXRPC_CALL_SERVER_AWAIT_ACK) && 675 hard > tx) 676 goto all_acked; 677 678 smp_rmb(); 679 rxrpc_rotate_tx_window(call, hard - 1); 680 } 681 682 if (ack.nAcks > 0) { 683 if (hard - 1 + ack.nAcks > tx) { 684 _debug("soft-ACK'd packet %d+%d not" 685 " transmitted (%d top)", 686 hard - 1, ack.nAcks, tx); 687 goto protocol_error; 688 } 689 690 if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0) 691 goto protocol_error; 692 } 693 goto discard; 694 695 /* complete ACK to process */ 696 case RXRPC_PACKET_TYPE_ACKALL: 697 goto all_acked; 698 699 /* abort and busy are handled elsewhere */ 700 case RXRPC_PACKET_TYPE_BUSY: 701 case RXRPC_PACKET_TYPE_ABORT: 702 BUG(); 703 704 /* connection level events - also handled elsewhere */ 705 case RXRPC_PACKET_TYPE_CHALLENGE: 706 case RXRPC_PACKET_TYPE_RESPONSE: 707 case RXRPC_PACKET_TYPE_DEBUG: 708 BUG(); 709 } 710 711 /* if we've had a hard ACK that covers all the packets we've sent, then 712 * that ends that phase of the operation */ 713all_acked: 714 write_lock_bh(&call->state_lock); 715 _debug("ack all %d", call->state); 716 717 switch (call->state) { 718 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 719 call->state = RXRPC_CALL_CLIENT_RECV_REPLY; 720 break; 721 case RXRPC_CALL_SERVER_AWAIT_ACK: 722 _debug("srv complete"); 723 call->state = RXRPC_CALL_COMPLETE; 724 post_ACK = true; 725 break; 726 case RXRPC_CALL_CLIENT_SEND_REQUEST: 727 case RXRPC_CALL_SERVER_RECV_REQUEST: 728 goto protocol_error_unlock; /* can't occur yet */ 729 default: 730 write_unlock_bh(&call->state_lock); 731 goto discard; /* assume packet left over from earlier phase */ 732 } 733 734 write_unlock_bh(&call->state_lock); 735 736 /* if all the packets we sent are hard-ACK'd, then we can discard 737 * whatever we've got left */ 738 _debug("clear Tx %d", 739 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz)); 740 741 del_timer_sync(&call->resend_timer); 742 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 743 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events); 744 745 if (call->acks_window) 746 rxrpc_zap_tx_window(call); 747 748 if (post_ACK) { 749 /* post the final ACK message for userspace to pick up */ 750 _debug("post ACK"); 751 skb->mark = RXRPC_SKB_MARK_FINAL_ACK; 752 sp->call = call; 753 rxrpc_get_call(call); 754 spin_lock_bh(&call->lock); 755 if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0) 756 BUG(); 757 spin_unlock_bh(&call->lock); 758 goto process_further; 759 } 760 761discard: 762 rxrpc_free_skb(skb); 763 goto process_further; 764 765protocol_error_unlock: 766 write_unlock_bh(&call->state_lock); 767protocol_error: 768 rxrpc_free_skb(skb); 769 _leave(" = -EPROTO"); 770 return -EPROTO; 771} 772 773/* 774 * post a message to the socket Rx queue for recvmsg() to pick up 775 */ 776static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error, 777 bool fatal) 778{ 779 struct rxrpc_skb_priv *sp; 780 struct sk_buff *skb; 781 int ret; 782 783 _enter("{%d,%lx},%u,%u,%d", 784 call->debug_id, call->flags, mark, error, fatal); 785 786 /* remove timers and things for fatal messages */ 787 if (fatal) { 788 del_timer_sync(&call->resend_timer); 789 del_timer_sync(&call->ack_timer); 790 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 791 } 792 793 if (mark != RXRPC_SKB_MARK_NEW_CALL && 794 !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 795 _leave("[no userid]"); 796 return 0; 797 } 798 799 if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) { 800 skb = alloc_skb(0, GFP_NOFS); 801 if (!skb) 802 return -ENOMEM; 803 804 rxrpc_new_skb(skb); 805 806 skb->mark = mark; 807 808 sp = rxrpc_skb(skb); 809 memset(sp, 0, sizeof(*sp)); 810 sp->error = error; 811 sp->call = call; 812 rxrpc_get_call(call); 813 814 spin_lock_bh(&call->lock); 815 ret = rxrpc_queue_rcv_skb(call, skb, true, fatal); 816 spin_unlock_bh(&call->lock); 817 if (ret < 0) 818 BUG(); 819 } 820 821 return 0; 822} 823 824/* 825 * handle background processing of incoming call packets and ACK / abort 826 * generation 827 */ 828void rxrpc_process_call(struct work_struct *work) 829{ 830 struct rxrpc_call *call = 831 container_of(work, struct rxrpc_call, processor); 832 struct rxrpc_ackpacket ack; 833 struct rxrpc_ackinfo ackinfo; 834 struct rxrpc_header hdr; 835 struct msghdr msg; 836 struct kvec iov[5]; 837 unsigned long bits; 838 __be32 data, pad; 839 size_t len; 840 int genbit, loop, nbit, ioc, ret, mtu; 841 u32 abort_code = RX_PROTOCOL_ERROR; 842 u8 *acks = NULL; 843 844 //printk("\n--------------------\n"); 845 _enter("{%d,%s,%lx} [%lu]", 846 call->debug_id, rxrpc_call_states[call->state], call->events, 847 (jiffies - call->creation_jif) / (HZ / 10)); 848 849 if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) { 850 _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX"); 851 return; 852 } 853 854 /* there's a good chance we're going to have to send a message, so set 855 * one up in advance */ 856 msg.msg_name = &call->conn->trans->peer->srx.transport.sin; 857 msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin); 858 msg.msg_control = NULL; 859 msg.msg_controllen = 0; 860 msg.msg_flags = 0; 861 862 hdr.epoch = call->conn->epoch; 863 hdr.cid = call->cid; 864 hdr.callNumber = call->call_id; 865 hdr.seq = 0; 866 hdr.type = RXRPC_PACKET_TYPE_ACK; 867 hdr.flags = call->conn->out_clientflag; 868 hdr.userStatus = 0; 869 hdr.securityIndex = call->conn->security_ix; 870 hdr._rsvd = 0; 871 hdr.serviceId = call->conn->service_id; 872 873 memset(iov, 0, sizeof(iov)); 874 iov[0].iov_base = &hdr; 875 iov[0].iov_len = sizeof(hdr); 876 877 /* deal with events of a final nature */ 878 if (test_bit(RXRPC_CALL_RELEASE, &call->events)) { 879 rxrpc_release_call(call); 880 clear_bit(RXRPC_CALL_RELEASE, &call->events); 881 } 882 883 if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) { 884 int error; 885 886 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events); 887 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events); 888 clear_bit(RXRPC_CALL_ABORT, &call->events); 889 890 error = call->conn->trans->peer->net_error; 891 _debug("post net error %d", error); 892 893 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR, 894 error, true) < 0) 895 goto no_mem; 896 clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events); 897 goto kill_ACKs; 898 } 899 900 if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) { 901 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE); 902 903 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events); 904 clear_bit(RXRPC_CALL_ABORT, &call->events); 905 906 _debug("post conn abort"); 907 908 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 909 call->conn->error, true) < 0) 910 goto no_mem; 911 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events); 912 goto kill_ACKs; 913 } 914 915 if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) { 916 hdr.type = RXRPC_PACKET_TYPE_BUSY; 917 genbit = RXRPC_CALL_REJECT_BUSY; 918 goto send_message; 919 } 920 921 if (test_bit(RXRPC_CALL_ABORT, &call->events)) { 922 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE); 923 924 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 925 ECONNABORTED, true) < 0) 926 goto no_mem; 927 hdr.type = RXRPC_PACKET_TYPE_ABORT; 928 data = htonl(call->abort_code); 929 iov[1].iov_base = &data; 930 iov[1].iov_len = sizeof(data); 931 genbit = RXRPC_CALL_ABORT; 932 goto send_message; 933 } 934 935 if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) { 936 genbit = RXRPC_CALL_ACK_FINAL; 937 938 ack.bufferSpace = htons(8); 939 ack.maxSkew = 0; 940 ack.serial = 0; 941 ack.reason = RXRPC_ACK_IDLE; 942 ack.nAcks = 0; 943 call->ackr_reason = 0; 944 945 spin_lock_bh(&call->lock); 946 ack.serial = call->ackr_serial; 947 ack.previousPacket = call->ackr_prev_seq; 948 ack.firstPacket = htonl(call->rx_data_eaten + 1); 949 spin_unlock_bh(&call->lock); 950 951 pad = 0; 952 953 iov[1].iov_base = &ack; 954 iov[1].iov_len = sizeof(ack); 955 iov[2].iov_base = &pad; 956 iov[2].iov_len = 3; 957 iov[3].iov_base = &ackinfo; 958 iov[3].iov_len = sizeof(ackinfo); 959 goto send_ACK; 960 } 961 962 if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) | 963 (1 << RXRPC_CALL_RCVD_ABORT)) 964 ) { 965 u32 mark; 966 967 if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events)) 968 mark = RXRPC_SKB_MARK_REMOTE_ABORT; 969 else 970 mark = RXRPC_SKB_MARK_BUSY; 971 972 _debug("post abort/busy"); 973 rxrpc_clear_tx_window(call); 974 if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0) 975 goto no_mem; 976 977 clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events); 978 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events); 979 goto kill_ACKs; 980 } 981 982 if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) { 983 _debug("do implicit ackall"); 984 rxrpc_clear_tx_window(call); 985 } 986 987 if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) { 988 write_lock_bh(&call->state_lock); 989 if (call->state <= RXRPC_CALL_COMPLETE) { 990 call->state = RXRPC_CALL_LOCALLY_ABORTED; 991 call->abort_code = RX_CALL_TIMEOUT; 992 set_bit(RXRPC_CALL_ABORT, &call->events); 993 } 994 write_unlock_bh(&call->state_lock); 995 996 _debug("post timeout"); 997 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 998 ETIME, true) < 0) 999 goto no_mem; 1000 1001 clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events); 1002 goto kill_ACKs; 1003 } 1004 1005 /* deal with assorted inbound messages */ 1006 if (!skb_queue_empty(&call->rx_queue)) { 1007 switch (rxrpc_process_rx_queue(call, &abort_code)) { 1008 case 0: 1009 case -EAGAIN: 1010 break; 1011 case -ENOMEM: 1012 goto no_mem; 1013 case -EKEYEXPIRED: 1014 case -EKEYREJECTED: 1015 case -EPROTO: 1016 rxrpc_abort_call(call, abort_code); 1017 goto kill_ACKs; 1018 } 1019 } 1020 1021 /* handle resending */ 1022 if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events)) 1023 rxrpc_resend_timer(call); 1024 if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events)) 1025 rxrpc_resend(call); 1026 1027 /* consider sending an ordinary ACK */ 1028 if (test_bit(RXRPC_CALL_ACK, &call->events)) { 1029 _debug("send ACK: window: %d - %d { %lx }", 1030 call->rx_data_eaten, call->ackr_win_top, 1031 call->ackr_window[0]); 1032 1033 if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST && 1034 call->ackr_reason != RXRPC_ACK_PING_RESPONSE) { 1035 /* ACK by sending reply DATA packet in this state */ 1036 clear_bit(RXRPC_CALL_ACK, &call->events); 1037 goto maybe_reschedule; 1038 } 1039 1040 genbit = RXRPC_CALL_ACK; 1041 1042 acks = kzalloc(call->ackr_win_top - call->rx_data_eaten, 1043 GFP_NOFS); 1044 if (!acks) 1045 goto no_mem; 1046 1047 //hdr.flags = RXRPC_SLOW_START_OK; 1048 ack.bufferSpace = htons(8); 1049 ack.maxSkew = 0; 1050 ack.serial = 0; 1051 ack.reason = 0; 1052 1053 spin_lock_bh(&call->lock); 1054 ack.reason = call->ackr_reason; 1055 ack.serial = call->ackr_serial; 1056 ack.previousPacket = call->ackr_prev_seq; 1057 ack.firstPacket = htonl(call->rx_data_eaten + 1); 1058 1059 ack.nAcks = 0; 1060 for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) { 1061 nbit = loop * BITS_PER_LONG; 1062 for (bits = call->ackr_window[loop]; bits; bits >>= 1 1063 ) { 1064 _debug("- l=%d n=%d b=%lx", loop, nbit, bits); 1065 if (bits & 1) { 1066 acks[nbit] = RXRPC_ACK_TYPE_ACK; 1067 ack.nAcks = nbit + 1; 1068 } 1069 nbit++; 1070 } 1071 } 1072 call->ackr_reason = 0; 1073 spin_unlock_bh(&call->lock); 1074 1075 pad = 0; 1076 1077 iov[1].iov_base = &ack; 1078 iov[1].iov_len = sizeof(ack); 1079 iov[2].iov_base = acks; 1080 iov[2].iov_len = ack.nAcks; 1081 iov[3].iov_base = &pad; 1082 iov[3].iov_len = 3; 1083 iov[4].iov_base = &ackinfo; 1084 iov[4].iov_len = sizeof(ackinfo); 1085 1086 switch (ack.reason) { 1087 case RXRPC_ACK_REQUESTED: 1088 case RXRPC_ACK_DUPLICATE: 1089 case RXRPC_ACK_OUT_OF_SEQUENCE: 1090 case RXRPC_ACK_EXCEEDS_WINDOW: 1091 case RXRPC_ACK_NOSPACE: 1092 case RXRPC_ACK_PING: 1093 case RXRPC_ACK_PING_RESPONSE: 1094 goto send_ACK_with_skew; 1095 case RXRPC_ACK_DELAY: 1096 case RXRPC_ACK_IDLE: 1097 goto send_ACK; 1098 } 1099 } 1100 1101 /* handle completion of security negotiations on an incoming 1102 * connection */ 1103 if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) { 1104 _debug("secured"); 1105 spin_lock_bh(&call->lock); 1106 1107 if (call->state == RXRPC_CALL_SERVER_SECURING) { 1108 _debug("securing"); 1109 write_lock(&call->conn->lock); 1110 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 1111 !test_bit(RXRPC_CALL_RELEASE, &call->events)) { 1112 _debug("not released"); 1113 call->state = RXRPC_CALL_SERVER_ACCEPTING; 1114 list_move_tail(&call->accept_link, 1115 &call->socket->acceptq); 1116 } 1117 write_unlock(&call->conn->lock); 1118 read_lock(&call->state_lock); 1119 if (call->state < RXRPC_CALL_COMPLETE) 1120 set_bit(RXRPC_CALL_POST_ACCEPT, &call->events); 1121 read_unlock(&call->state_lock); 1122 } 1123 1124 spin_unlock_bh(&call->lock); 1125 if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) 1126 goto maybe_reschedule; 1127 } 1128 1129 /* post a notification of an acceptable connection to the app */ 1130 if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) { 1131 _debug("post accept"); 1132 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL, 1133 0, false) < 0) 1134 goto no_mem; 1135 clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events); 1136 goto maybe_reschedule; 1137 } 1138 1139 /* handle incoming call acceptance */ 1140 if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) { 1141 _debug("accepted"); 1142 ASSERTCMP(call->rx_data_post, ==, 0); 1143 call->rx_data_post = 1; 1144 read_lock_bh(&call->state_lock); 1145 if (call->state < RXRPC_CALL_COMPLETE) 1146 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events); 1147 read_unlock_bh(&call->state_lock); 1148 } 1149 1150 /* drain the out of sequence received packet queue into the packet Rx 1151 * queue */ 1152 if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) { 1153 while (call->rx_data_post == call->rx_first_oos) 1154 if (rxrpc_drain_rx_oos_queue(call) < 0) 1155 break; 1156 goto maybe_reschedule; 1157 } 1158 1159 /* other events may have been raised since we started checking */ 1160 goto maybe_reschedule; 1161 1162send_ACK_with_skew: 1163 ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) - 1164 ntohl(ack.serial)); 1165send_ACK: 1166 mtu = call->conn->trans->peer->if_mtu; 1167 mtu -= call->conn->trans->peer->hdrsize; 1168 ackinfo.maxMTU = htonl(mtu); 1169 ackinfo.rwind = htonl(32); 1170 1171 /* permit the peer to send us jumbo packets if it wants to */ 1172 ackinfo.rxMTU = htonl(5692); 1173 ackinfo.jumbo_max = htonl(4); 1174 1175 hdr.serial = htonl(atomic_inc_return(&call->conn->serial)); 1176 _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", 1177 ntohl(hdr.serial), 1178 ntohs(ack.maxSkew), 1179 ntohl(ack.firstPacket), 1180 ntohl(ack.previousPacket), 1181 ntohl(ack.serial), 1182 rxrpc_acks[ack.reason], 1183 ack.nAcks); 1184 1185 del_timer_sync(&call->ack_timer); 1186 if (ack.nAcks > 0) 1187 set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags); 1188 goto send_message_2; 1189 1190send_message: 1191 _debug("send message"); 1192 1193 hdr.serial = htonl(atomic_inc_return(&call->conn->serial)); 1194 _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial)); 1195send_message_2: 1196 1197 len = iov[0].iov_len; 1198 ioc = 1; 1199 if (iov[4].iov_len) { 1200 ioc = 5; 1201 len += iov[4].iov_len; 1202 len += iov[3].iov_len; 1203 len += iov[2].iov_len; 1204 len += iov[1].iov_len; 1205 } else if (iov[3].iov_len) { 1206 ioc = 4; 1207 len += iov[3].iov_len; 1208 len += iov[2].iov_len; 1209 len += iov[1].iov_len; 1210 } else if (iov[2].iov_len) { 1211 ioc = 3; 1212 len += iov[2].iov_len; 1213 len += iov[1].iov_len; 1214 } else if (iov[1].iov_len) { 1215 ioc = 2; 1216 len += iov[1].iov_len; 1217 } 1218 1219 ret = kernel_sendmsg(call->conn->trans->local->socket, 1220 &msg, iov, ioc, len); 1221 if (ret < 0) { 1222 _debug("sendmsg failed: %d", ret); 1223 read_lock_bh(&call->state_lock); 1224 if (call->state < RXRPC_CALL_DEAD) 1225 rxrpc_queue_call(call); 1226 read_unlock_bh(&call->state_lock); 1227 goto error; 1228 } 1229 1230 switch (genbit) { 1231 case RXRPC_CALL_ABORT: 1232 clear_bit(genbit, &call->events); 1233 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events); 1234 goto kill_ACKs; 1235 1236 case RXRPC_CALL_ACK_FINAL: 1237 write_lock_bh(&call->state_lock); 1238 if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK) 1239 call->state = RXRPC_CALL_COMPLETE; 1240 write_unlock_bh(&call->state_lock); 1241 goto kill_ACKs; 1242 1243 default: 1244 clear_bit(genbit, &call->events); 1245 switch (call->state) { 1246 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 1247 case RXRPC_CALL_CLIENT_RECV_REPLY: 1248 case RXRPC_CALL_SERVER_RECV_REQUEST: 1249 case RXRPC_CALL_SERVER_ACK_REQUEST: 1250 _debug("start ACK timer"); 1251 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 1252 call->ackr_serial, false); 1253 default: 1254 break; 1255 } 1256 goto maybe_reschedule; 1257 } 1258 1259kill_ACKs: 1260 del_timer_sync(&call->ack_timer); 1261 if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events)) 1262 rxrpc_put_call(call); 1263 clear_bit(RXRPC_CALL_ACK, &call->events); 1264 1265maybe_reschedule: 1266 if (call->events || !skb_queue_empty(&call->rx_queue)) { 1267 read_lock_bh(&call->state_lock); 1268 if (call->state < RXRPC_CALL_DEAD) 1269 rxrpc_queue_call(call); 1270 read_unlock_bh(&call->state_lock); 1271 } 1272 1273 /* don't leave aborted connections on the accept queue */ 1274 if (call->state >= RXRPC_CALL_COMPLETE && 1275 !list_empty(&call->accept_link)) { 1276 _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }", 1277 call, call->events, call->flags, 1278 ntohl(call->conn->cid)); 1279 1280 read_lock_bh(&call->state_lock); 1281 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 1282 !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) 1283 rxrpc_queue_call(call); 1284 read_unlock_bh(&call->state_lock); 1285 } 1286 1287error: 1288 clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags); 1289 kfree(acks); 1290 1291 /* because we don't want two CPUs both processing the work item for one 1292 * call at the same time, we use a flag to note when it's busy; however 1293 * this means there's a race between clearing the flag and setting the 1294 * work pending bit and the work item being processed again */ 1295 if (call->events && !work_pending(&call->processor)) { 1296 _debug("jumpstart %x", ntohl(call->conn->cid)); 1297 rxrpc_queue_call(call); 1298 } 1299 1300 _leave(""); 1301 return; 1302 1303no_mem: 1304 _debug("out of memory"); 1305 goto maybe_reschedule; 1306} 1307