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 22static unsigned int rxrpc_ack_defer = 1; 23 24static const char *const rxrpc_acks[] = { 25 "---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY", "IDL", 26 "-?-" 27}; 28 29static const s8 rxrpc_ack_priority[] = { 30 [0] = 0, 31 [RXRPC_ACK_DELAY] = 1, 32 [RXRPC_ACK_REQUESTED] = 2, 33 [RXRPC_ACK_IDLE] = 3, 34 [RXRPC_ACK_PING_RESPONSE] = 4, 35 [RXRPC_ACK_DUPLICATE] = 5, 36 [RXRPC_ACK_OUT_OF_SEQUENCE] = 6, 37 [RXRPC_ACK_EXCEEDS_WINDOW] = 7, 38 [RXRPC_ACK_NOSPACE] = 8, 39}; 40 41/* 42 * propose an ACK be sent 43 */ 44void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason, 45 __be32 serial, bool immediate) 46{ 47 unsigned long expiry; 48 s8 prior = rxrpc_ack_priority[ack_reason]; 49 50 ASSERTCMP(prior, >, 0); 51 52 _enter("{%d},%s,%%%x,%u", 53 call->debug_id, rxrpc_acks[ack_reason], ntohl(serial), 54 immediate); 55 56 if (prior < rxrpc_ack_priority[call->ackr_reason]) { 57 if (immediate) 58 goto cancel_timer; 59 return; 60 } 61 62 /* update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial 63 * numbers */ 64 if (prior == rxrpc_ack_priority[call->ackr_reason]) { 65 if (prior <= 4) 66 call->ackr_serial = serial; 67 if (immediate) 68 goto cancel_timer; 69 return; 70 } 71 72 call->ackr_reason = ack_reason; 73 call->ackr_serial = serial; 74 75 switch (ack_reason) { 76 case RXRPC_ACK_DELAY: 77 _debug("run delay timer"); 78 call->ack_timer.expires = jiffies + rxrpc_ack_timeout * HZ; 79 add_timer(&call->ack_timer); 80 return; 81 82 case RXRPC_ACK_IDLE: 83 if (!immediate) { 84 _debug("run defer timer"); 85 expiry = 1; 86 goto run_timer; 87 } 88 goto cancel_timer; 89 90 case RXRPC_ACK_REQUESTED: 91 if (!rxrpc_ack_defer) 92 goto cancel_timer; 93 if (!immediate || serial == cpu_to_be32(1)) { 94 _debug("run defer timer"); 95 expiry = rxrpc_ack_defer; 96 goto run_timer; 97 } 98 99 default: 100 _debug("immediate ACK"); 101 goto cancel_timer; 102 } 103 104run_timer: 105 expiry += jiffies; 106 if (!timer_pending(&call->ack_timer) || 107 time_after(call->ack_timer.expires, expiry)) 108 mod_timer(&call->ack_timer, expiry); 109 return; 110 111cancel_timer: 112 _debug("cancel timer %%%u", ntohl(serial)); 113 try_to_del_timer_sync(&call->ack_timer); 114 read_lock_bh(&call->state_lock); 115 if (call->state <= RXRPC_CALL_COMPLETE && 116 !test_and_set_bit(RXRPC_CALL_ACK, &call->events)) 117 rxrpc_queue_call(call); 118 read_unlock_bh(&call->state_lock); 119} 120 121/* 122 * propose an ACK be sent, locking the call structure 123 */ 124void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason, 125 __be32 serial, bool immediate) 126{ 127 s8 prior = rxrpc_ack_priority[ack_reason]; 128 129 if (prior > rxrpc_ack_priority[call->ackr_reason]) { 130 spin_lock_bh(&call->lock); 131 __rxrpc_propose_ACK(call, ack_reason, serial, immediate); 132 spin_unlock_bh(&call->lock); 133 } 134} 135 136/* 137 * set the resend timer 138 */ 139static void rxrpc_set_resend(struct rxrpc_call *call, u8 resend, 140 unsigned long resend_at) 141{ 142 read_lock_bh(&call->state_lock); 143 if (call->state >= RXRPC_CALL_COMPLETE) 144 resend = 0; 145 146 if (resend & 1) { 147 _debug("SET RESEND"); 148 set_bit(RXRPC_CALL_RESEND, &call->events); 149 } 150 151 if (resend & 2) { 152 _debug("MODIFY RESEND TIMER"); 153 set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 154 mod_timer(&call->resend_timer, resend_at); 155 } else { 156 _debug("KILL RESEND TIMER"); 157 del_timer_sync(&call->resend_timer); 158 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events); 159 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 160 } 161 read_unlock_bh(&call->state_lock); 162} 163 164/* 165 * resend packets 166 */ 167static void rxrpc_resend(struct rxrpc_call *call) 168{ 169 struct rxrpc_skb_priv *sp; 170 struct rxrpc_header *hdr; 171 struct sk_buff *txb; 172 unsigned long *p_txb, resend_at; 173 int loop, stop; 174 u8 resend; 175 176 _enter("{%d,%d,%d,%d},", 177 call->acks_hard, call->acks_unacked, 178 atomic_read(&call->sequence), 179 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz)); 180 181 stop = 0; 182 resend = 0; 183 resend_at = 0; 184 185 for (loop = call->acks_tail; 186 loop != call->acks_head || stop; 187 loop = (loop + 1) & (call->acks_winsz - 1) 188 ) { 189 p_txb = call->acks_window + loop; 190 smp_read_barrier_depends(); 191 if (*p_txb & 1) 192 continue; 193 194 txb = (struct sk_buff *) *p_txb; 195 sp = rxrpc_skb(txb); 196 197 if (sp->need_resend) { 198 sp->need_resend = false; 199 200 /* each Tx packet has a new serial number */ 201 sp->hdr.serial = 202 htonl(atomic_inc_return(&call->conn->serial)); 203 204 hdr = (struct rxrpc_header *) txb->head; 205 hdr->serial = sp->hdr.serial; 206 207 _proto("Tx DATA %%%u { #%d }", 208 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq)); 209 if (rxrpc_send_packet(call->conn->trans, txb) < 0) { 210 stop = 0; 211 sp->resend_at = jiffies + 3; 212 } else { 213 sp->resend_at = 214 jiffies + rxrpc_resend_timeout * HZ; 215 } 216 } 217 218 if (time_after_eq(jiffies + 1, sp->resend_at)) { 219 sp->need_resend = true; 220 resend |= 1; 221 } else if (resend & 2) { 222 if (time_before(sp->resend_at, resend_at)) 223 resend_at = sp->resend_at; 224 } else { 225 resend_at = sp->resend_at; 226 resend |= 2; 227 } 228 } 229 230 rxrpc_set_resend(call, resend, resend_at); 231 _leave(""); 232} 233 234/* 235 * handle resend timer expiry 236 */ 237static void rxrpc_resend_timer(struct rxrpc_call *call) 238{ 239 struct rxrpc_skb_priv *sp; 240 struct sk_buff *txb; 241 unsigned long *p_txb, resend_at; 242 int loop; 243 u8 resend; 244 245 _enter("%d,%d,%d", 246 call->acks_tail, call->acks_unacked, call->acks_head); 247 248 if (call->state >= RXRPC_CALL_COMPLETE) 249 return; 250 251 resend = 0; 252 resend_at = 0; 253 254 for (loop = call->acks_unacked; 255 loop != call->acks_head; 256 loop = (loop + 1) & (call->acks_winsz - 1) 257 ) { 258 p_txb = call->acks_window + loop; 259 smp_read_barrier_depends(); 260 txb = (struct sk_buff *) (*p_txb & ~1); 261 sp = rxrpc_skb(txb); 262 263 ASSERT(!(*p_txb & 1)); 264 265 if (sp->need_resend) { 266 ; 267 } else 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 * process soft ACKs of our transmitted packets 285 * - these indicate packets the peer has or has not received, but hasn't yet 286 * given to the consumer, and so can still be discarded and re-requested 287 */ 288static int rxrpc_process_soft_ACKs(struct rxrpc_call *call, 289 struct rxrpc_ackpacket *ack, 290 struct sk_buff *skb) 291{ 292 struct rxrpc_skb_priv *sp; 293 struct sk_buff *txb; 294 unsigned long *p_txb, resend_at; 295 int loop; 296 u8 sacks[RXRPC_MAXACKS], resend; 297 298 _enter("{%d,%d},{%d},", 299 call->acks_hard, 300 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz), 301 ack->nAcks); 302 303 if (skb_copy_bits(skb, 0, sacks, ack->nAcks) < 0) 304 goto protocol_error; 305 306 resend = 0; 307 resend_at = 0; 308 for (loop = 0; loop < ack->nAcks; loop++) { 309 p_txb = call->acks_window; 310 p_txb += (call->acks_tail + loop) & (call->acks_winsz - 1); 311 smp_read_barrier_depends(); 312 txb = (struct sk_buff *) (*p_txb & ~1); 313 sp = rxrpc_skb(txb); 314 315 switch (sacks[loop]) { 316 case RXRPC_ACK_TYPE_ACK: 317 sp->need_resend = false; 318 *p_txb |= 1; 319 break; 320 case RXRPC_ACK_TYPE_NACK: 321 sp->need_resend = true; 322 *p_txb &= ~1; 323 resend = 1; 324 break; 325 default: 326 _debug("Unsupported ACK type %d", sacks[loop]); 327 goto protocol_error; 328 } 329 } 330 331 smp_mb(); 332 call->acks_unacked = (call->acks_tail + loop) & (call->acks_winsz - 1); 333 334 /* anything not explicitly ACK'd is implicitly NACK'd, but may just not 335 * have been received or processed yet by the far end */ 336 for (loop = call->acks_unacked; 337 loop != call->acks_head; 338 loop = (loop + 1) & (call->acks_winsz - 1) 339 ) { 340 p_txb = call->acks_window + loop; 341 smp_read_barrier_depends(); 342 txb = (struct sk_buff *) (*p_txb & ~1); 343 sp = rxrpc_skb(txb); 344 345 if (*p_txb & 1) { 346 /* packet must have been discarded */ 347 sp->need_resend = true; 348 *p_txb &= ~1; 349 resend |= 1; 350 } else if (sp->need_resend) { 351 ; 352 } else if (time_after_eq(jiffies + 1, sp->resend_at)) { 353 sp->need_resend = true; 354 resend |= 1; 355 } else if (resend & 2) { 356 if (time_before(sp->resend_at, resend_at)) 357 resend_at = sp->resend_at; 358 } else { 359 resend_at = sp->resend_at; 360 resend |= 2; 361 } 362 } 363 364 rxrpc_set_resend(call, resend, resend_at); 365 _leave(" = 0"); 366 return 0; 367 368protocol_error: 369 _leave(" = -EPROTO"); 370 return -EPROTO; 371} 372 373/* 374 * discard hard-ACK'd packets from the Tx window 375 */ 376static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard) 377{ 378 unsigned long _skb; 379 int tail = call->acks_tail, old_tail; 380 int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz); 381 382 _enter("{%u,%u},%u", call->acks_hard, win, hard); 383 384 ASSERTCMP(hard - call->acks_hard, <=, win); 385 386 while (call->acks_hard < hard) { 387 smp_read_barrier_depends(); 388 _skb = call->acks_window[tail] & ~1; 389 rxrpc_free_skb((struct sk_buff *) _skb); 390 old_tail = tail; 391 tail = (tail + 1) & (call->acks_winsz - 1); 392 call->acks_tail = tail; 393 if (call->acks_unacked == old_tail) 394 call->acks_unacked = tail; 395 call->acks_hard++; 396 } 397 398 wake_up(&call->tx_waitq); 399} 400 401/* 402 * clear the Tx window in the event of a failure 403 */ 404static void rxrpc_clear_tx_window(struct rxrpc_call *call) 405{ 406 rxrpc_rotate_tx_window(call, atomic_read(&call->sequence)); 407} 408 409/* 410 * drain the out of sequence received packet queue into the packet Rx queue 411 */ 412static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call) 413{ 414 struct rxrpc_skb_priv *sp; 415 struct sk_buff *skb; 416 bool terminal; 417 int ret; 418 419 _enter("{%d,%d}", call->rx_data_post, call->rx_first_oos); 420 421 spin_lock_bh(&call->lock); 422 423 ret = -ECONNRESET; 424 if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) 425 goto socket_unavailable; 426 427 skb = skb_dequeue(&call->rx_oos_queue); 428 if (skb) { 429 sp = rxrpc_skb(skb); 430 431 _debug("drain OOS packet %d [%d]", 432 ntohl(sp->hdr.seq), call->rx_first_oos); 433 434 if (ntohl(sp->hdr.seq) != call->rx_first_oos) { 435 skb_queue_head(&call->rx_oos_queue, skb); 436 call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq); 437 _debug("requeue %p {%u}", skb, call->rx_first_oos); 438 } else { 439 skb->mark = RXRPC_SKB_MARK_DATA; 440 terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) && 441 !(sp->hdr.flags & RXRPC_CLIENT_INITIATED)); 442 ret = rxrpc_queue_rcv_skb(call, skb, true, terminal); 443 BUG_ON(ret < 0); 444 _debug("drain #%u", call->rx_data_post); 445 call->rx_data_post++; 446 447 /* find out what the next packet is */ 448 skb = skb_peek(&call->rx_oos_queue); 449 if (skb) 450 call->rx_first_oos = 451 ntohl(rxrpc_skb(skb)->hdr.seq); 452 else 453 call->rx_first_oos = 0; 454 _debug("peek %p {%u}", skb, call->rx_first_oos); 455 } 456 } 457 458 ret = 0; 459socket_unavailable: 460 spin_unlock_bh(&call->lock); 461 _leave(" = %d", ret); 462 return ret; 463} 464 465/* 466 * insert an out of sequence packet into the buffer 467 */ 468static void rxrpc_insert_oos_packet(struct rxrpc_call *call, 469 struct sk_buff *skb) 470{ 471 struct rxrpc_skb_priv *sp, *psp; 472 struct sk_buff *p; 473 u32 seq; 474 475 sp = rxrpc_skb(skb); 476 seq = ntohl(sp->hdr.seq); 477 _enter(",,{%u}", seq); 478 479 skb->destructor = rxrpc_packet_destructor; 480 ASSERTCMP(sp->call, ==, NULL); 481 sp->call = call; 482 rxrpc_get_call(call); 483 484 /* insert into the buffer in sequence order */ 485 spin_lock_bh(&call->lock); 486 487 skb_queue_walk(&call->rx_oos_queue, p) { 488 psp = rxrpc_skb(p); 489 if (ntohl(psp->hdr.seq) > seq) { 490 _debug("insert oos #%u before #%u", 491 seq, ntohl(psp->hdr.seq)); 492 skb_insert(p, skb, &call->rx_oos_queue); 493 goto inserted; 494 } 495 } 496 497 _debug("append oos #%u", seq); 498 skb_queue_tail(&call->rx_oos_queue, skb); 499inserted: 500 501 /* we might now have a new front to the queue */ 502 if (call->rx_first_oos == 0 || seq < call->rx_first_oos) 503 call->rx_first_oos = seq; 504 505 read_lock(&call->state_lock); 506 if (call->state < RXRPC_CALL_COMPLETE && 507 call->rx_data_post == call->rx_first_oos) { 508 _debug("drain rx oos now"); 509 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events); 510 } 511 read_unlock(&call->state_lock); 512 513 spin_unlock_bh(&call->lock); 514 _leave(" [stored #%u]", call->rx_first_oos); 515} 516 517/* 518 * clear the Tx window on final ACK reception 519 */ 520static void rxrpc_zap_tx_window(struct rxrpc_call *call) 521{ 522 struct rxrpc_skb_priv *sp; 523 struct sk_buff *skb; 524 unsigned long _skb, *acks_window; 525 u8 winsz = call->acks_winsz; 526 int tail; 527 528 acks_window = call->acks_window; 529 call->acks_window = NULL; 530 531 while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) { 532 tail = call->acks_tail; 533 smp_read_barrier_depends(); 534 _skb = acks_window[tail] & ~1; 535 smp_mb(); 536 call->acks_tail = (call->acks_tail + 1) & (winsz - 1); 537 538 skb = (struct sk_buff *) _skb; 539 sp = rxrpc_skb(skb); 540 _debug("+++ clear Tx %u", ntohl(sp->hdr.seq)); 541 rxrpc_free_skb(skb); 542 } 543 544 kfree(acks_window); 545} 546 547/* 548 * process the extra information that may be appended to an ACK packet 549 */ 550static void rxrpc_extract_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 551 unsigned int latest, int nAcks) 552{ 553 struct rxrpc_ackinfo ackinfo; 554 struct rxrpc_peer *peer; 555 unsigned int mtu; 556 557 if (skb_copy_bits(skb, nAcks + 3, &ackinfo, sizeof(ackinfo)) < 0) { 558 _leave(" [no ackinfo]"); 559 return; 560 } 561 562 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 563 latest, 564 ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU), 565 ntohl(ackinfo.rwind), ntohl(ackinfo.jumbo_max)); 566 567 mtu = min(ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU)); 568 569 peer = call->conn->trans->peer; 570 if (mtu < peer->maxdata) { 571 spin_lock_bh(&peer->lock); 572 peer->maxdata = mtu; 573 peer->mtu = mtu + peer->hdrsize; 574 spin_unlock_bh(&peer->lock); 575 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 576 } 577} 578 579/* 580 * process packets in the reception queue 581 */ 582static int rxrpc_process_rx_queue(struct rxrpc_call *call, 583 u32 *_abort_code) 584{ 585 struct rxrpc_ackpacket ack; 586 struct rxrpc_skb_priv *sp; 587 struct sk_buff *skb; 588 bool post_ACK; 589 int latest; 590 u32 hard, tx; 591 592 _enter(""); 593 594process_further: 595 skb = skb_dequeue(&call->rx_queue); 596 if (!skb) 597 return -EAGAIN; 598 599 _net("deferred skb %p", skb); 600 601 sp = rxrpc_skb(skb); 602 603 _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state); 604 605 post_ACK = false; 606 607 switch (sp->hdr.type) { 608 /* data packets that wind up here have been received out of 609 * order, need security processing or are jumbo packets */ 610 case RXRPC_PACKET_TYPE_DATA: 611 _proto("OOSQ DATA %%%u { #%u }", 612 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq)); 613 614 /* secured packets must be verified and possibly decrypted */ 615 if (rxrpc_verify_packet(call, skb, _abort_code) < 0) 616 goto protocol_error; 617 618 rxrpc_insert_oos_packet(call, skb); 619 goto process_further; 620 621 /* partial ACK to process */ 622 case RXRPC_PACKET_TYPE_ACK: 623 if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) { 624 _debug("extraction failure"); 625 goto protocol_error; 626 } 627 if (!skb_pull(skb, sizeof(ack))) 628 BUG(); 629 630 latest = ntohl(sp->hdr.serial); 631 hard = ntohl(ack.firstPacket); 632 tx = atomic_read(&call->sequence); 633 634 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", 635 latest, 636 ntohs(ack.maxSkew), 637 hard, 638 ntohl(ack.previousPacket), 639 ntohl(ack.serial), 640 rxrpc_acks[ack.reason], 641 ack.nAcks); 642 643 rxrpc_extract_ackinfo(call, skb, latest, ack.nAcks); 644 645 if (ack.reason == RXRPC_ACK_PING) { 646 _proto("Rx ACK %%%u PING Request", latest); 647 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 648 sp->hdr.serial, true); 649 } 650 651 /* discard any out-of-order or duplicate ACKs */ 652 if (latest - call->acks_latest <= 0) { 653 _debug("discard ACK %d <= %d", 654 latest, call->acks_latest); 655 goto discard; 656 } 657 call->acks_latest = latest; 658 659 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST && 660 call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY && 661 call->state != RXRPC_CALL_SERVER_SEND_REPLY && 662 call->state != RXRPC_CALL_SERVER_AWAIT_ACK) 663 goto discard; 664 665 _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state); 666 667 if (hard > 0) { 668 if (hard - 1 > tx) { 669 _debug("hard-ACK'd packet %d not transmitted" 670 " (%d top)", 671 hard - 1, tx); 672 goto protocol_error; 673 } 674 675 if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY || 676 call->state == RXRPC_CALL_SERVER_AWAIT_ACK) && 677 hard > tx) 678 goto all_acked; 679 680 smp_rmb(); 681 rxrpc_rotate_tx_window(call, hard - 1); 682 } 683 684 if (ack.nAcks > 0) { 685 if (hard - 1 + ack.nAcks > tx) { 686 _debug("soft-ACK'd packet %d+%d not" 687 " transmitted (%d top)", 688 hard - 1, ack.nAcks, tx); 689 goto protocol_error; 690 } 691 692 if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0) 693 goto protocol_error; 694 } 695 goto discard; 696 697 /* complete ACK to process */ 698 case RXRPC_PACKET_TYPE_ACKALL: 699 goto all_acked; 700 701 /* abort and busy are handled elsewhere */ 702 case RXRPC_PACKET_TYPE_BUSY: 703 case RXRPC_PACKET_TYPE_ABORT: 704 BUG(); 705 706 /* connection level events - also handled elsewhere */ 707 case RXRPC_PACKET_TYPE_CHALLENGE: 708 case RXRPC_PACKET_TYPE_RESPONSE: 709 case RXRPC_PACKET_TYPE_DEBUG: 710 BUG(); 711 } 712 713 /* if we've had a hard ACK that covers all the packets we've sent, then 714 * that ends that phase of the operation */ 715all_acked: 716 write_lock_bh(&call->state_lock); 717 _debug("ack all %d", call->state); 718 719 switch (call->state) { 720 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 721 call->state = RXRPC_CALL_CLIENT_RECV_REPLY; 722 break; 723 case RXRPC_CALL_SERVER_AWAIT_ACK: 724 _debug("srv complete"); 725 call->state = RXRPC_CALL_COMPLETE; 726 post_ACK = true; 727 break; 728 case RXRPC_CALL_CLIENT_SEND_REQUEST: 729 case RXRPC_CALL_SERVER_RECV_REQUEST: 730 goto protocol_error_unlock; /* can't occur yet */ 731 default: 732 write_unlock_bh(&call->state_lock); 733 goto discard; /* assume packet left over from earlier phase */ 734 } 735 736 write_unlock_bh(&call->state_lock); 737 738 /* if all the packets we sent are hard-ACK'd, then we can discard 739 * whatever we've got left */ 740 _debug("clear Tx %d", 741 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz)); 742 743 del_timer_sync(&call->resend_timer); 744 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 745 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events); 746 747 if (call->acks_window) 748 rxrpc_zap_tx_window(call); 749 750 if (post_ACK) { 751 /* post the final ACK message for userspace to pick up */ 752 _debug("post ACK"); 753 skb->mark = RXRPC_SKB_MARK_FINAL_ACK; 754 sp->call = call; 755 rxrpc_get_call(call); 756 spin_lock_bh(&call->lock); 757 if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0) 758 BUG(); 759 spin_unlock_bh(&call->lock); 760 goto process_further; 761 } 762 763discard: 764 rxrpc_free_skb(skb); 765 goto process_further; 766 767protocol_error_unlock: 768 write_unlock_bh(&call->state_lock); 769protocol_error: 770 rxrpc_free_skb(skb); 771 _leave(" = -EPROTO"); 772 return -EPROTO; 773} 774 775/* 776 * post a message to the socket Rx queue for recvmsg() to pick up 777 */ 778static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error, 779 bool fatal) 780{ 781 struct rxrpc_skb_priv *sp; 782 struct sk_buff *skb; 783 int ret; 784 785 _enter("{%d,%lx},%u,%u,%d", 786 call->debug_id, call->flags, mark, error, fatal); 787 788 /* remove timers and things for fatal messages */ 789 if (fatal) { 790 del_timer_sync(&call->resend_timer); 791 del_timer_sync(&call->ack_timer); 792 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 793 } 794 795 if (mark != RXRPC_SKB_MARK_NEW_CALL && 796 !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 797 _leave("[no userid]"); 798 return 0; 799 } 800 801 if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) { 802 skb = alloc_skb(0, GFP_NOFS); 803 if (!skb) 804 return -ENOMEM; 805 806 rxrpc_new_skb(skb); 807 808 skb->mark = mark; 809 810 sp = rxrpc_skb(skb); 811 memset(sp, 0, sizeof(*sp)); 812 sp->error = error; 813 sp->call = call; 814 rxrpc_get_call(call); 815 816 spin_lock_bh(&call->lock); 817 ret = rxrpc_queue_rcv_skb(call, skb, true, fatal); 818 spin_unlock_bh(&call->lock); 819 BUG_ON(ret < 0); 820 } 821 822 return 0; 823} 824 825/* 826 * handle background processing of incoming call packets and ACK / abort 827 * generation 828 */ 829void rxrpc_process_call(struct work_struct *work) 830{ 831 struct rxrpc_call *call = 832 container_of(work, struct rxrpc_call, processor); 833 struct rxrpc_ackpacket ack; 834 struct rxrpc_ackinfo ackinfo; 835 struct rxrpc_header hdr; 836 struct msghdr msg; 837 struct kvec iov[5]; 838 unsigned long bits; 839 __be32 data, pad; 840 size_t len; 841 int genbit, loop, nbit, ioc, ret, mtu; 842 u32 abort_code = RX_PROTOCOL_ERROR; 843 u8 *acks = NULL; 844 845 //printk("\n--------------------\n"); 846 _enter("{%d,%s,%lx} [%lu]", 847 call->debug_id, rxrpc_call_states[call->state], call->events, 848 (jiffies - call->creation_jif) / (HZ / 10)); 849 850 if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) { 851 _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX"); 852 return; 853 } 854 855 /* there's a good chance we're going to have to send a message, so set 856 * one up in advance */ 857 msg.msg_name = &call->conn->trans->peer->srx.transport.sin; 858 msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin); 859 msg.msg_control = NULL; 860 msg.msg_controllen = 0; 861 msg.msg_flags = 0; 862 863 hdr.epoch = call->conn->epoch; 864 hdr.cid = call->cid; 865 hdr.callNumber = call->call_id; 866 hdr.seq = 0; 867 hdr.type = RXRPC_PACKET_TYPE_ACK; 868 hdr.flags = call->conn->out_clientflag; 869 hdr.userStatus = 0; 870 hdr.securityIndex = call->conn->security_ix; 871 hdr._rsvd = 0; 872 hdr.serviceId = call->conn->service_id; 873 874 memset(iov, 0, sizeof(iov)); 875 iov[0].iov_base = &hdr; 876 iov[0].iov_len = sizeof(hdr); 877 878 /* deal with events of a final nature */ 879 if (test_bit(RXRPC_CALL_RELEASE, &call->events)) { 880 rxrpc_release_call(call); 881 clear_bit(RXRPC_CALL_RELEASE, &call->events); 882 } 883 884 if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) { 885 int error; 886 887 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events); 888 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events); 889 clear_bit(RXRPC_CALL_ABORT, &call->events); 890 891 error = call->conn->trans->peer->net_error; 892 _debug("post net error %d", error); 893 894 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR, 895 error, true) < 0) 896 goto no_mem; 897 clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events); 898 goto kill_ACKs; 899 } 900 901 if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) { 902 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE); 903 904 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events); 905 clear_bit(RXRPC_CALL_ABORT, &call->events); 906 907 _debug("post conn abort"); 908 909 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 910 call->conn->error, true) < 0) 911 goto no_mem; 912 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events); 913 goto kill_ACKs; 914 } 915 916 if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) { 917 hdr.type = RXRPC_PACKET_TYPE_BUSY; 918 genbit = RXRPC_CALL_REJECT_BUSY; 919 goto send_message; 920 } 921 922 if (test_bit(RXRPC_CALL_ABORT, &call->events)) { 923 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE); 924 925 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 926 ECONNABORTED, true) < 0) 927 goto no_mem; 928 hdr.type = RXRPC_PACKET_TYPE_ABORT; 929 data = htonl(call->abort_code); 930 iov[1].iov_base = &data; 931 iov[1].iov_len = sizeof(data); 932 genbit = RXRPC_CALL_ABORT; 933 goto send_message; 934 } 935 936 if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) { 937 genbit = RXRPC_CALL_ACK_FINAL; 938 939 ack.bufferSpace = htons(8); 940 ack.maxSkew = 0; 941 ack.serial = 0; 942 ack.reason = RXRPC_ACK_IDLE; 943 ack.nAcks = 0; 944 call->ackr_reason = 0; 945 946 spin_lock_bh(&call->lock); 947 ack.serial = call->ackr_serial; 948 ack.previousPacket = call->ackr_prev_seq; 949 ack.firstPacket = htonl(call->rx_data_eaten + 1); 950 spin_unlock_bh(&call->lock); 951 952 pad = 0; 953 954 iov[1].iov_base = &ack; 955 iov[1].iov_len = sizeof(ack); 956 iov[2].iov_base = &pad; 957 iov[2].iov_len = 3; 958 iov[3].iov_base = &ackinfo; 959 iov[3].iov_len = sizeof(ackinfo); 960 goto send_ACK; 961 } 962 963 if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) | 964 (1 << RXRPC_CALL_RCVD_ABORT)) 965 ) { 966 u32 mark; 967 968 if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events)) 969 mark = RXRPC_SKB_MARK_REMOTE_ABORT; 970 else 971 mark = RXRPC_SKB_MARK_BUSY; 972 973 _debug("post abort/busy"); 974 rxrpc_clear_tx_window(call); 975 if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0) 976 goto no_mem; 977 978 clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events); 979 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events); 980 goto kill_ACKs; 981 } 982 983 if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) { 984 _debug("do implicit ackall"); 985 rxrpc_clear_tx_window(call); 986 } 987 988 if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) { 989 write_lock_bh(&call->state_lock); 990 if (call->state <= RXRPC_CALL_COMPLETE) { 991 call->state = RXRPC_CALL_LOCALLY_ABORTED; 992 call->abort_code = RX_CALL_TIMEOUT; 993 set_bit(RXRPC_CALL_ABORT, &call->events); 994 } 995 write_unlock_bh(&call->state_lock); 996 997 _debug("post timeout"); 998 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 999 ETIME, true) < 0) 1000 goto no_mem; 1001 1002 clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events); 1003 goto kill_ACKs; 1004 } 1005 1006 /* deal with assorted inbound messages */ 1007 if (!skb_queue_empty(&call->rx_queue)) { 1008 switch (rxrpc_process_rx_queue(call, &abort_code)) { 1009 case 0: 1010 case -EAGAIN: 1011 break; 1012 case -ENOMEM: 1013 goto no_mem; 1014 case -EKEYEXPIRED: 1015 case -EKEYREJECTED: 1016 case -EPROTO: 1017 rxrpc_abort_call(call, abort_code); 1018 goto kill_ACKs; 1019 } 1020 } 1021 1022 /* handle resending */ 1023 if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events)) 1024 rxrpc_resend_timer(call); 1025 if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events)) 1026 rxrpc_resend(call); 1027 1028 /* consider sending an ordinary ACK */ 1029 if (test_bit(RXRPC_CALL_ACK, &call->events)) { 1030 _debug("send ACK: window: %d - %d { %lx }", 1031 call->rx_data_eaten, call->ackr_win_top, 1032 call->ackr_window[0]); 1033 1034 if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST && 1035 call->ackr_reason != RXRPC_ACK_PING_RESPONSE) { 1036 /* ACK by sending reply DATA packet in this state */ 1037 clear_bit(RXRPC_CALL_ACK, &call->events); 1038 goto maybe_reschedule; 1039 } 1040 1041 genbit = RXRPC_CALL_ACK; 1042 1043 acks = kzalloc(call->ackr_win_top - call->rx_data_eaten, 1044 GFP_NOFS); 1045 if (!acks) 1046 goto no_mem; 1047 1048 //hdr.flags = RXRPC_SLOW_START_OK; 1049 ack.bufferSpace = htons(8); 1050 ack.maxSkew = 0; 1051 ack.serial = 0; 1052 ack.reason = 0; 1053 1054 spin_lock_bh(&call->lock); 1055 ack.reason = call->ackr_reason; 1056 ack.serial = call->ackr_serial; 1057 ack.previousPacket = call->ackr_prev_seq; 1058 ack.firstPacket = htonl(call->rx_data_eaten + 1); 1059 1060 ack.nAcks = 0; 1061 for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) { 1062 nbit = loop * BITS_PER_LONG; 1063 for (bits = call->ackr_window[loop]; bits; bits >>= 1 1064 ) { 1065 _debug("- l=%d n=%d b=%lx", loop, nbit, bits); 1066 if (bits & 1) { 1067 acks[nbit] = RXRPC_ACK_TYPE_ACK; 1068 ack.nAcks = nbit + 1; 1069 } 1070 nbit++; 1071 } 1072 } 1073 call->ackr_reason = 0; 1074 spin_unlock_bh(&call->lock); 1075 1076 pad = 0; 1077 1078 iov[1].iov_base = &ack; 1079 iov[1].iov_len = sizeof(ack); 1080 iov[2].iov_base = acks; 1081 iov[2].iov_len = ack.nAcks; 1082 iov[3].iov_base = &pad; 1083 iov[3].iov_len = 3; 1084 iov[4].iov_base = &ackinfo; 1085 iov[4].iov_len = sizeof(ackinfo); 1086 1087 switch (ack.reason) { 1088 case RXRPC_ACK_REQUESTED: 1089 case RXRPC_ACK_DUPLICATE: 1090 case RXRPC_ACK_OUT_OF_SEQUENCE: 1091 case RXRPC_ACK_EXCEEDS_WINDOW: 1092 case RXRPC_ACK_NOSPACE: 1093 case RXRPC_ACK_PING: 1094 case RXRPC_ACK_PING_RESPONSE: 1095 goto send_ACK_with_skew; 1096 case RXRPC_ACK_DELAY: 1097 case RXRPC_ACK_IDLE: 1098 goto send_ACK; 1099 } 1100 } 1101 1102 /* handle completion of security negotiations on an incoming 1103 * connection */ 1104 if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) { 1105 _debug("secured"); 1106 spin_lock_bh(&call->lock); 1107 1108 if (call->state == RXRPC_CALL_SERVER_SECURING) { 1109 _debug("securing"); 1110 write_lock(&call->conn->lock); 1111 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 1112 !test_bit(RXRPC_CALL_RELEASE, &call->events)) { 1113 _debug("not released"); 1114 call->state = RXRPC_CALL_SERVER_ACCEPTING; 1115 list_move_tail(&call->accept_link, 1116 &call->socket->acceptq); 1117 } 1118 write_unlock(&call->conn->lock); 1119 read_lock(&call->state_lock); 1120 if (call->state < RXRPC_CALL_COMPLETE) 1121 set_bit(RXRPC_CALL_POST_ACCEPT, &call->events); 1122 read_unlock(&call->state_lock); 1123 } 1124 1125 spin_unlock_bh(&call->lock); 1126 if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) 1127 goto maybe_reschedule; 1128 } 1129 1130 /* post a notification of an acceptable connection to the app */ 1131 if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) { 1132 _debug("post accept"); 1133 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL, 1134 0, false) < 0) 1135 goto no_mem; 1136 clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events); 1137 goto maybe_reschedule; 1138 } 1139 1140 /* handle incoming call acceptance */ 1141 if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) { 1142 _debug("accepted"); 1143 ASSERTCMP(call->rx_data_post, ==, 0); 1144 call->rx_data_post = 1; 1145 read_lock_bh(&call->state_lock); 1146 if (call->state < RXRPC_CALL_COMPLETE) 1147 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events); 1148 read_unlock_bh(&call->state_lock); 1149 } 1150 1151 /* drain the out of sequence received packet queue into the packet Rx 1152 * queue */ 1153 if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) { 1154 while (call->rx_data_post == call->rx_first_oos) 1155 if (rxrpc_drain_rx_oos_queue(call) < 0) 1156 break; 1157 goto maybe_reschedule; 1158 } 1159 1160 /* other events may have been raised since we started checking */ 1161 goto maybe_reschedule; 1162 1163send_ACK_with_skew: 1164 ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) - 1165 ntohl(ack.serial)); 1166send_ACK: 1167 mtu = call->conn->trans->peer->if_mtu; 1168 mtu -= call->conn->trans->peer->hdrsize; 1169 ackinfo.maxMTU = htonl(mtu); 1170 ackinfo.rwind = htonl(32); 1171 1172 /* permit the peer to send us jumbo packets if it wants to */ 1173 ackinfo.rxMTU = htonl(5692); 1174 ackinfo.jumbo_max = htonl(4); 1175 1176 hdr.serial = htonl(atomic_inc_return(&call->conn->serial)); 1177 _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", 1178 ntohl(hdr.serial), 1179 ntohs(ack.maxSkew), 1180 ntohl(ack.firstPacket), 1181 ntohl(ack.previousPacket), 1182 ntohl(ack.serial), 1183 rxrpc_acks[ack.reason], 1184 ack.nAcks); 1185 1186 del_timer_sync(&call->ack_timer); 1187 if (ack.nAcks > 0) 1188 set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags); 1189 goto send_message_2; 1190 1191send_message: 1192 _debug("send message"); 1193 1194 hdr.serial = htonl(atomic_inc_return(&call->conn->serial)); 1195 _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial)); 1196send_message_2: 1197 1198 len = iov[0].iov_len; 1199 ioc = 1; 1200 if (iov[4].iov_len) { 1201 ioc = 5; 1202 len += iov[4].iov_len; 1203 len += iov[3].iov_len; 1204 len += iov[2].iov_len; 1205 len += iov[1].iov_len; 1206 } else if (iov[3].iov_len) { 1207 ioc = 4; 1208 len += iov[3].iov_len; 1209 len += iov[2].iov_len; 1210 len += iov[1].iov_len; 1211 } else if (iov[2].iov_len) { 1212 ioc = 3; 1213 len += iov[2].iov_len; 1214 len += iov[1].iov_len; 1215 } else if (iov[1].iov_len) { 1216 ioc = 2; 1217 len += iov[1].iov_len; 1218 } 1219 1220 ret = kernel_sendmsg(call->conn->trans->local->socket, 1221 &msg, iov, ioc, len); 1222 if (ret < 0) { 1223 _debug("sendmsg failed: %d", ret); 1224 read_lock_bh(&call->state_lock); 1225 if (call->state < RXRPC_CALL_DEAD) 1226 rxrpc_queue_call(call); 1227 read_unlock_bh(&call->state_lock); 1228 goto error; 1229 } 1230 1231 switch (genbit) { 1232 case RXRPC_CALL_ABORT: 1233 clear_bit(genbit, &call->events); 1234 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events); 1235 goto kill_ACKs; 1236 1237 case RXRPC_CALL_ACK_FINAL: 1238 write_lock_bh(&call->state_lock); 1239 if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK) 1240 call->state = RXRPC_CALL_COMPLETE; 1241 write_unlock_bh(&call->state_lock); 1242 goto kill_ACKs; 1243 1244 default: 1245 clear_bit(genbit, &call->events); 1246 switch (call->state) { 1247 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 1248 case RXRPC_CALL_CLIENT_RECV_REPLY: 1249 case RXRPC_CALL_SERVER_RECV_REQUEST: 1250 case RXRPC_CALL_SERVER_ACK_REQUEST: 1251 _debug("start ACK timer"); 1252 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 1253 call->ackr_serial, false); 1254 default: 1255 break; 1256 } 1257 goto maybe_reschedule; 1258 } 1259 1260kill_ACKs: 1261 del_timer_sync(&call->ack_timer); 1262 if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events)) 1263 rxrpc_put_call(call); 1264 clear_bit(RXRPC_CALL_ACK, &call->events); 1265 1266maybe_reschedule: 1267 if (call->events || !skb_queue_empty(&call->rx_queue)) { 1268 read_lock_bh(&call->state_lock); 1269 if (call->state < RXRPC_CALL_DEAD) 1270 rxrpc_queue_call(call); 1271 read_unlock_bh(&call->state_lock); 1272 } 1273 1274 /* don't leave aborted connections on the accept queue */ 1275 if (call->state >= RXRPC_CALL_COMPLETE && 1276 !list_empty(&call->accept_link)) { 1277 _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }", 1278 call, call->events, call->flags, 1279 ntohl(call->conn->cid)); 1280 1281 read_lock_bh(&call->state_lock); 1282 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 1283 !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) 1284 rxrpc_queue_call(call); 1285 read_unlock_bh(&call->state_lock); 1286 } 1287 1288error: 1289 clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags); 1290 kfree(acks); 1291 1292 /* because we don't want two CPUs both processing the work item for one 1293 * call at the same time, we use a flag to note when it's busy; however 1294 * this means there's a race between clearing the flag and setting the 1295 * work pending bit and the work item being processed again */ 1296 if (call->events && !work_pending(&call->processor)) { 1297 _debug("jumpstart %x", ntohl(call->conn->cid)); 1298 rxrpc_queue_call(call); 1299 } 1300 1301 _leave(""); 1302 return; 1303 1304no_mem: 1305 _debug("out of memory"); 1306 goto maybe_reschedule; 1307} 1308