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 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 = 0; 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 = 1; 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 = 1; 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 = 0; 318 *p_txb |= 1; 319 break; 320 case RXRPC_ACK_TYPE_NACK: 321 sp->need_resend = 1; 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 = 1; 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 = 1; 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 struct rxrpc_skb_priv *sp; 379 unsigned long _skb; 380 int tail = call->acks_tail, old_tail; 381 int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz); 382 383 _enter("{%u,%u},%u", call->acks_hard, win, hard); 384 385 ASSERTCMP(hard - call->acks_hard, <=, win); 386 387 while (call->acks_hard < hard) { 388 smp_read_barrier_depends(); 389 _skb = call->acks_window[tail] & ~1; 390 sp = rxrpc_skb((struct sk_buff *) _skb); 391 rxrpc_free_skb((struct sk_buff *) _skb); 392 old_tail = tail; 393 tail = (tail + 1) & (call->acks_winsz - 1); 394 call->acks_tail = tail; 395 if (call->acks_unacked == old_tail) 396 call->acks_unacked = tail; 397 call->acks_hard++; 398 } 399 400 wake_up(&call->tx_waitq); 401} 402 403/* 404 * clear the Tx window in the event of a failure 405 */ 406static void rxrpc_clear_tx_window(struct rxrpc_call *call) 407{ 408 rxrpc_rotate_tx_window(call, atomic_read(&call->sequence)); 409} 410 411/* 412 * drain the out of sequence received packet queue into the packet Rx queue 413 */ 414static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call) 415{ 416 struct rxrpc_skb_priv *sp; 417 struct sk_buff *skb; 418 bool terminal; 419 int ret; 420 421 _enter("{%d,%d}", call->rx_data_post, call->rx_first_oos); 422 423 spin_lock_bh(&call->lock); 424 425 ret = -ECONNRESET; 426 if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) 427 goto socket_unavailable; 428 429 skb = skb_dequeue(&call->rx_oos_queue); 430 if (skb) { 431 sp = rxrpc_skb(skb); 432 433 _debug("drain OOS packet %d [%d]", 434 ntohl(sp->hdr.seq), call->rx_first_oos); 435 436 if (ntohl(sp->hdr.seq) != call->rx_first_oos) { 437 skb_queue_head(&call->rx_oos_queue, skb); 438 call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq); 439 _debug("requeue %p {%u}", skb, call->rx_first_oos); 440 } else { 441 skb->mark = RXRPC_SKB_MARK_DATA; 442 terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) && 443 !(sp->hdr.flags & RXRPC_CLIENT_INITIATED)); 444 ret = rxrpc_queue_rcv_skb(call, skb, true, terminal); 445 BUG_ON(ret < 0); 446 _debug("drain #%u", call->rx_data_post); 447 call->rx_data_post++; 448 449 /* find out what the next packet is */ 450 skb = skb_peek(&call->rx_oos_queue); 451 if (skb) 452 call->rx_first_oos = 453 ntohl(rxrpc_skb(skb)->hdr.seq); 454 else 455 call->rx_first_oos = 0; 456 _debug("peek %p {%u}", skb, call->rx_first_oos); 457 } 458 } 459 460 ret = 0; 461socket_unavailable: 462 spin_unlock_bh(&call->lock); 463 _leave(" = %d", ret); 464 return ret; 465} 466 467/* 468 * insert an out of sequence packet into the buffer 469 */ 470static void rxrpc_insert_oos_packet(struct rxrpc_call *call, 471 struct sk_buff *skb) 472{ 473 struct rxrpc_skb_priv *sp, *psp; 474 struct sk_buff *p; 475 u32 seq; 476 477 sp = rxrpc_skb(skb); 478 seq = ntohl(sp->hdr.seq); 479 _enter(",,{%u}", seq); 480 481 skb->destructor = rxrpc_packet_destructor; 482 ASSERTCMP(sp->call, ==, NULL); 483 sp->call = call; 484 rxrpc_get_call(call); 485 486 /* insert into the buffer in sequence order */ 487 spin_lock_bh(&call->lock); 488 489 skb_queue_walk(&call->rx_oos_queue, p) { 490 psp = rxrpc_skb(p); 491 if (ntohl(psp->hdr.seq) > seq) { 492 _debug("insert oos #%u before #%u", 493 seq, ntohl(psp->hdr.seq)); 494 skb_insert(p, skb, &call->rx_oos_queue); 495 goto inserted; 496 } 497 } 498 499 _debug("append oos #%u", seq); 500 skb_queue_tail(&call->rx_oos_queue, skb); 501inserted: 502 503 /* we might now have a new front to the queue */ 504 if (call->rx_first_oos == 0 || seq < call->rx_first_oos) 505 call->rx_first_oos = seq; 506 507 read_lock(&call->state_lock); 508 if (call->state < RXRPC_CALL_COMPLETE && 509 call->rx_data_post == call->rx_first_oos) { 510 _debug("drain rx oos now"); 511 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events); 512 } 513 read_unlock(&call->state_lock); 514 515 spin_unlock_bh(&call->lock); 516 _leave(" [stored #%u]", call->rx_first_oos); 517} 518 519/* 520 * clear the Tx window on final ACK reception 521 */ 522static void rxrpc_zap_tx_window(struct rxrpc_call *call) 523{ 524 struct rxrpc_skb_priv *sp; 525 struct sk_buff *skb; 526 unsigned long _skb, *acks_window; 527 u8 winsz = call->acks_winsz; 528 int tail; 529 530 acks_window = call->acks_window; 531 call->acks_window = NULL; 532 533 while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) { 534 tail = call->acks_tail; 535 smp_read_barrier_depends(); 536 _skb = acks_window[tail] & ~1; 537 smp_mb(); 538 call->acks_tail = (call->acks_tail + 1) & (winsz - 1); 539 540 skb = (struct sk_buff *) _skb; 541 sp = rxrpc_skb(skb); 542 _debug("+++ clear Tx %u", ntohl(sp->hdr.seq)); 543 rxrpc_free_skb(skb); 544 } 545 546 kfree(acks_window); 547} 548 549/* 550 * process the extra information that may be appended to an ACK packet 551 */ 552static void rxrpc_extract_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 553 unsigned latest, int nAcks) 554{ 555 struct rxrpc_ackinfo ackinfo; 556 struct rxrpc_peer *peer; 557 unsigned mtu; 558 559 if (skb_copy_bits(skb, nAcks + 3, &ackinfo, sizeof(ackinfo)) < 0) { 560 _leave(" [no ackinfo]"); 561 return; 562 } 563 564 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 565 latest, 566 ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU), 567 ntohl(ackinfo.rwind), ntohl(ackinfo.jumbo_max)); 568 569 mtu = min(ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU)); 570 571 peer = call->conn->trans->peer; 572 if (mtu < peer->maxdata) { 573 spin_lock_bh(&peer->lock); 574 peer->maxdata = mtu; 575 peer->mtu = mtu + peer->hdrsize; 576 spin_unlock_bh(&peer->lock); 577 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 578 } 579} 580 581/* 582 * process packets in the reception queue 583 */ 584static int rxrpc_process_rx_queue(struct rxrpc_call *call, 585 u32 *_abort_code) 586{ 587 struct rxrpc_ackpacket ack; 588 struct rxrpc_skb_priv *sp; 589 struct sk_buff *skb; 590 bool post_ACK; 591 int latest; 592 u32 hard, tx; 593 594 _enter(""); 595 596process_further: 597 skb = skb_dequeue(&call->rx_queue); 598 if (!skb) 599 return -EAGAIN; 600 601 _net("deferred skb %p", skb); 602 603 sp = rxrpc_skb(skb); 604 605 _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state); 606 607 post_ACK = false; 608 609 switch (sp->hdr.type) { 610 /* data packets that wind up here have been received out of 611 * order, need security processing or are jumbo packets */ 612 case RXRPC_PACKET_TYPE_DATA: 613 _proto("OOSQ DATA %%%u { #%u }", 614 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq)); 615 616 /* secured packets must be verified and possibly decrypted */ 617 if (rxrpc_verify_packet(call, skb, _abort_code) < 0) 618 goto protocol_error; 619 620 rxrpc_insert_oos_packet(call, skb); 621 goto process_further; 622 623 /* partial ACK to process */ 624 case RXRPC_PACKET_TYPE_ACK: 625 if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) { 626 _debug("extraction failure"); 627 goto protocol_error; 628 } 629 if (!skb_pull(skb, sizeof(ack))) 630 BUG(); 631 632 latest = ntohl(sp->hdr.serial); 633 hard = ntohl(ack.firstPacket); 634 tx = atomic_read(&call->sequence); 635 636 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", 637 latest, 638 ntohs(ack.maxSkew), 639 hard, 640 ntohl(ack.previousPacket), 641 ntohl(ack.serial), 642 rxrpc_acks[ack.reason], 643 ack.nAcks); 644 645 rxrpc_extract_ackinfo(call, skb, latest, ack.nAcks); 646 647 if (ack.reason == RXRPC_ACK_PING) { 648 _proto("Rx ACK %%%u PING Request", latest); 649 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 650 sp->hdr.serial, true); 651 } 652 653 /* discard any out-of-order or duplicate ACKs */ 654 if (latest - call->acks_latest <= 0) { 655 _debug("discard ACK %d <= %d", 656 latest, call->acks_latest); 657 goto discard; 658 } 659 call->acks_latest = latest; 660 661 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST && 662 call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY && 663 call->state != RXRPC_CALL_SERVER_SEND_REPLY && 664 call->state != RXRPC_CALL_SERVER_AWAIT_ACK) 665 goto discard; 666 667 _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state); 668 669 if (hard > 0) { 670 if (hard - 1 > tx) { 671 _debug("hard-ACK'd packet %d not transmitted" 672 " (%d top)", 673 hard - 1, tx); 674 goto protocol_error; 675 } 676 677 if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY || 678 call->state == RXRPC_CALL_SERVER_AWAIT_ACK) && 679 hard > tx) 680 goto all_acked; 681 682 smp_rmb(); 683 rxrpc_rotate_tx_window(call, hard - 1); 684 } 685 686 if (ack.nAcks > 0) { 687 if (hard - 1 + ack.nAcks > tx) { 688 _debug("soft-ACK'd packet %d+%d not" 689 " transmitted (%d top)", 690 hard - 1, ack.nAcks, tx); 691 goto protocol_error; 692 } 693 694 if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0) 695 goto protocol_error; 696 } 697 goto discard; 698 699 /* complete ACK to process */ 700 case RXRPC_PACKET_TYPE_ACKALL: 701 goto all_acked; 702 703 /* abort and busy are handled elsewhere */ 704 case RXRPC_PACKET_TYPE_BUSY: 705 case RXRPC_PACKET_TYPE_ABORT: 706 BUG(); 707 708 /* connection level events - also handled elsewhere */ 709 case RXRPC_PACKET_TYPE_CHALLENGE: 710 case RXRPC_PACKET_TYPE_RESPONSE: 711 case RXRPC_PACKET_TYPE_DEBUG: 712 BUG(); 713 } 714 715 /* if we've had a hard ACK that covers all the packets we've sent, then 716 * that ends that phase of the operation */ 717all_acked: 718 write_lock_bh(&call->state_lock); 719 _debug("ack all %d", call->state); 720 721 switch (call->state) { 722 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 723 call->state = RXRPC_CALL_CLIENT_RECV_REPLY; 724 break; 725 case RXRPC_CALL_SERVER_AWAIT_ACK: 726 _debug("srv complete"); 727 call->state = RXRPC_CALL_COMPLETE; 728 post_ACK = true; 729 break; 730 case RXRPC_CALL_CLIENT_SEND_REQUEST: 731 case RXRPC_CALL_SERVER_RECV_REQUEST: 732 goto protocol_error_unlock; /* can't occur yet */ 733 default: 734 write_unlock_bh(&call->state_lock); 735 goto discard; /* assume packet left over from earlier phase */ 736 } 737 738 write_unlock_bh(&call->state_lock); 739 740 /* if all the packets we sent are hard-ACK'd, then we can discard 741 * whatever we've got left */ 742 _debug("clear Tx %d", 743 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz)); 744 745 del_timer_sync(&call->resend_timer); 746 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 747 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events); 748 749 if (call->acks_window) 750 rxrpc_zap_tx_window(call); 751 752 if (post_ACK) { 753 /* post the final ACK message for userspace to pick up */ 754 _debug("post ACK"); 755 skb->mark = RXRPC_SKB_MARK_FINAL_ACK; 756 sp->call = call; 757 rxrpc_get_call(call); 758 spin_lock_bh(&call->lock); 759 if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0) 760 BUG(); 761 spin_unlock_bh(&call->lock); 762 goto process_further; 763 } 764 765discard: 766 rxrpc_free_skb(skb); 767 goto process_further; 768 769protocol_error_unlock: 770 write_unlock_bh(&call->state_lock); 771protocol_error: 772 rxrpc_free_skb(skb); 773 _leave(" = -EPROTO"); 774 return -EPROTO; 775} 776 777/* 778 * post a message to the socket Rx queue for recvmsg() to pick up 779 */ 780static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error, 781 bool fatal) 782{ 783 struct rxrpc_skb_priv *sp; 784 struct sk_buff *skb; 785 int ret; 786 787 _enter("{%d,%lx},%u,%u,%d", 788 call->debug_id, call->flags, mark, error, fatal); 789 790 /* remove timers and things for fatal messages */ 791 if (fatal) { 792 del_timer_sync(&call->resend_timer); 793 del_timer_sync(&call->ack_timer); 794 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); 795 } 796 797 if (mark != RXRPC_SKB_MARK_NEW_CALL && 798 !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 799 _leave("[no userid]"); 800 return 0; 801 } 802 803 if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) { 804 skb = alloc_skb(0, GFP_NOFS); 805 if (!skb) 806 return -ENOMEM; 807 808 rxrpc_new_skb(skb); 809 810 skb->mark = mark; 811 812 sp = rxrpc_skb(skb); 813 memset(sp, 0, sizeof(*sp)); 814 sp->error = error; 815 sp->call = call; 816 rxrpc_get_call(call); 817 818 spin_lock_bh(&call->lock); 819 ret = rxrpc_queue_rcv_skb(call, skb, true, fatal); 820 spin_unlock_bh(&call->lock); 821 BUG_ON(ret < 0); 822 } 823 824 return 0; 825} 826 827/* 828 * handle background processing of incoming call packets and ACK / abort 829 * generation 830 */ 831void rxrpc_process_call(struct work_struct *work) 832{ 833 struct rxrpc_call *call = 834 container_of(work, struct rxrpc_call, processor); 835 struct rxrpc_ackpacket ack; 836 struct rxrpc_ackinfo ackinfo; 837 struct rxrpc_header hdr; 838 struct msghdr msg; 839 struct kvec iov[5]; 840 unsigned long bits; 841 __be32 data, pad; 842 size_t len; 843 int genbit, loop, nbit, ioc, ret, mtu; 844 u32 abort_code = RX_PROTOCOL_ERROR; 845 u8 *acks = NULL; 846 847 //printk("\n--------------------\n"); 848 _enter("{%d,%s,%lx} [%lu]", 849 call->debug_id, rxrpc_call_states[call->state], call->events, 850 (jiffies - call->creation_jif) / (HZ / 10)); 851 852 if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) { 853 _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX"); 854 return; 855 } 856 857 /* there's a good chance we're going to have to send a message, so set 858 * one up in advance */ 859 msg.msg_name = &call->conn->trans->peer->srx.transport.sin; 860 msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin); 861 msg.msg_control = NULL; 862 msg.msg_controllen = 0; 863 msg.msg_flags = 0; 864 865 hdr.epoch = call->conn->epoch; 866 hdr.cid = call->cid; 867 hdr.callNumber = call->call_id; 868 hdr.seq = 0; 869 hdr.type = RXRPC_PACKET_TYPE_ACK; 870 hdr.flags = call->conn->out_clientflag; 871 hdr.userStatus = 0; 872 hdr.securityIndex = call->conn->security_ix; 873 hdr._rsvd = 0; 874 hdr.serviceId = call->conn->service_id; 875 876 memset(iov, 0, sizeof(iov)); 877 iov[0].iov_base = &hdr; 878 iov[0].iov_len = sizeof(hdr); 879 880 /* deal with events of a final nature */ 881 if (test_bit(RXRPC_CALL_RELEASE, &call->events)) { 882 rxrpc_release_call(call); 883 clear_bit(RXRPC_CALL_RELEASE, &call->events); 884 } 885 886 if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) { 887 int error; 888 889 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events); 890 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events); 891 clear_bit(RXRPC_CALL_ABORT, &call->events); 892 893 error = call->conn->trans->peer->net_error; 894 _debug("post net error %d", error); 895 896 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR, 897 error, true) < 0) 898 goto no_mem; 899 clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events); 900 goto kill_ACKs; 901 } 902 903 if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) { 904 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE); 905 906 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events); 907 clear_bit(RXRPC_CALL_ABORT, &call->events); 908 909 _debug("post conn abort"); 910 911 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 912 call->conn->error, true) < 0) 913 goto no_mem; 914 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events); 915 goto kill_ACKs; 916 } 917 918 if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) { 919 hdr.type = RXRPC_PACKET_TYPE_BUSY; 920 genbit = RXRPC_CALL_REJECT_BUSY; 921 goto send_message; 922 } 923 924 if (test_bit(RXRPC_CALL_ABORT, &call->events)) { 925 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE); 926 927 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 928 ECONNABORTED, true) < 0) 929 goto no_mem; 930 hdr.type = RXRPC_PACKET_TYPE_ABORT; 931 data = htonl(call->abort_code); 932 iov[1].iov_base = &data; 933 iov[1].iov_len = sizeof(data); 934 genbit = RXRPC_CALL_ABORT; 935 goto send_message; 936 } 937 938 if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) { 939 genbit = RXRPC_CALL_ACK_FINAL; 940 941 ack.bufferSpace = htons(8); 942 ack.maxSkew = 0; 943 ack.serial = 0; 944 ack.reason = RXRPC_ACK_IDLE; 945 ack.nAcks = 0; 946 call->ackr_reason = 0; 947 948 spin_lock_bh(&call->lock); 949 ack.serial = call->ackr_serial; 950 ack.previousPacket = call->ackr_prev_seq; 951 ack.firstPacket = htonl(call->rx_data_eaten + 1); 952 spin_unlock_bh(&call->lock); 953 954 pad = 0; 955 956 iov[1].iov_base = &ack; 957 iov[1].iov_len = sizeof(ack); 958 iov[2].iov_base = &pad; 959 iov[2].iov_len = 3; 960 iov[3].iov_base = &ackinfo; 961 iov[3].iov_len = sizeof(ackinfo); 962 goto send_ACK; 963 } 964 965 if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) | 966 (1 << RXRPC_CALL_RCVD_ABORT)) 967 ) { 968 u32 mark; 969 970 if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events)) 971 mark = RXRPC_SKB_MARK_REMOTE_ABORT; 972 else 973 mark = RXRPC_SKB_MARK_BUSY; 974 975 _debug("post abort/busy"); 976 rxrpc_clear_tx_window(call); 977 if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0) 978 goto no_mem; 979 980 clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events); 981 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events); 982 goto kill_ACKs; 983 } 984 985 if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) { 986 _debug("do implicit ackall"); 987 rxrpc_clear_tx_window(call); 988 } 989 990 if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) { 991 write_lock_bh(&call->state_lock); 992 if (call->state <= RXRPC_CALL_COMPLETE) { 993 call->state = RXRPC_CALL_LOCALLY_ABORTED; 994 call->abort_code = RX_CALL_TIMEOUT; 995 set_bit(RXRPC_CALL_ABORT, &call->events); 996 } 997 write_unlock_bh(&call->state_lock); 998 999 _debug("post timeout"); 1000 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR, 1001 ETIME, true) < 0) 1002 goto no_mem; 1003 1004 clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events); 1005 goto kill_ACKs; 1006 } 1007 1008 /* deal with assorted inbound messages */ 1009 if (!skb_queue_empty(&call->rx_queue)) { 1010 switch (rxrpc_process_rx_queue(call, &abort_code)) { 1011 case 0: 1012 case -EAGAIN: 1013 break; 1014 case -ENOMEM: 1015 goto no_mem; 1016 case -EKEYEXPIRED: 1017 case -EKEYREJECTED: 1018 case -EPROTO: 1019 rxrpc_abort_call(call, abort_code); 1020 goto kill_ACKs; 1021 } 1022 } 1023 1024 /* handle resending */ 1025 if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events)) 1026 rxrpc_resend_timer(call); 1027 if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events)) 1028 rxrpc_resend(call); 1029 1030 /* consider sending an ordinary ACK */ 1031 if (test_bit(RXRPC_CALL_ACK, &call->events)) { 1032 _debug("send ACK: window: %d - %d { %lx }", 1033 call->rx_data_eaten, call->ackr_win_top, 1034 call->ackr_window[0]); 1035 1036 if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST && 1037 call->ackr_reason != RXRPC_ACK_PING_RESPONSE) { 1038 /* ACK by sending reply DATA packet in this state */ 1039 clear_bit(RXRPC_CALL_ACK, &call->events); 1040 goto maybe_reschedule; 1041 } 1042 1043 genbit = RXRPC_CALL_ACK; 1044 1045 acks = kzalloc(call->ackr_win_top - call->rx_data_eaten, 1046 GFP_NOFS); 1047 if (!acks) 1048 goto no_mem; 1049 1050 //hdr.flags = RXRPC_SLOW_START_OK; 1051 ack.bufferSpace = htons(8); 1052 ack.maxSkew = 0; 1053 ack.serial = 0; 1054 ack.reason = 0; 1055 1056 spin_lock_bh(&call->lock); 1057 ack.reason = call->ackr_reason; 1058 ack.serial = call->ackr_serial; 1059 ack.previousPacket = call->ackr_prev_seq; 1060 ack.firstPacket = htonl(call->rx_data_eaten + 1); 1061 1062 ack.nAcks = 0; 1063 for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) { 1064 nbit = loop * BITS_PER_LONG; 1065 for (bits = call->ackr_window[loop]; bits; bits >>= 1 1066 ) { 1067 _debug("- l=%d n=%d b=%lx", loop, nbit, bits); 1068 if (bits & 1) { 1069 acks[nbit] = RXRPC_ACK_TYPE_ACK; 1070 ack.nAcks = nbit + 1; 1071 } 1072 nbit++; 1073 } 1074 } 1075 call->ackr_reason = 0; 1076 spin_unlock_bh(&call->lock); 1077 1078 pad = 0; 1079 1080 iov[1].iov_base = &ack; 1081 iov[1].iov_len = sizeof(ack); 1082 iov[2].iov_base = acks; 1083 iov[2].iov_len = ack.nAcks; 1084 iov[3].iov_base = &pad; 1085 iov[3].iov_len = 3; 1086 iov[4].iov_base = &ackinfo; 1087 iov[4].iov_len = sizeof(ackinfo); 1088 1089 switch (ack.reason) { 1090 case RXRPC_ACK_REQUESTED: 1091 case RXRPC_ACK_DUPLICATE: 1092 case RXRPC_ACK_OUT_OF_SEQUENCE: 1093 case RXRPC_ACK_EXCEEDS_WINDOW: 1094 case RXRPC_ACK_NOSPACE: 1095 case RXRPC_ACK_PING: 1096 case RXRPC_ACK_PING_RESPONSE: 1097 goto send_ACK_with_skew; 1098 case RXRPC_ACK_DELAY: 1099 case RXRPC_ACK_IDLE: 1100 goto send_ACK; 1101 } 1102 } 1103 1104 /* handle completion of security negotiations on an incoming 1105 * connection */ 1106 if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) { 1107 _debug("secured"); 1108 spin_lock_bh(&call->lock); 1109 1110 if (call->state == RXRPC_CALL_SERVER_SECURING) { 1111 _debug("securing"); 1112 write_lock(&call->conn->lock); 1113 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 1114 !test_bit(RXRPC_CALL_RELEASE, &call->events)) { 1115 _debug("not released"); 1116 call->state = RXRPC_CALL_SERVER_ACCEPTING; 1117 list_move_tail(&call->accept_link, 1118 &call->socket->acceptq); 1119 } 1120 write_unlock(&call->conn->lock); 1121 read_lock(&call->state_lock); 1122 if (call->state < RXRPC_CALL_COMPLETE) 1123 set_bit(RXRPC_CALL_POST_ACCEPT, &call->events); 1124 read_unlock(&call->state_lock); 1125 } 1126 1127 spin_unlock_bh(&call->lock); 1128 if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) 1129 goto maybe_reschedule; 1130 } 1131 1132 /* post a notification of an acceptable connection to the app */ 1133 if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) { 1134 _debug("post accept"); 1135 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL, 1136 0, false) < 0) 1137 goto no_mem; 1138 clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events); 1139 goto maybe_reschedule; 1140 } 1141 1142 /* handle incoming call acceptance */ 1143 if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) { 1144 _debug("accepted"); 1145 ASSERTCMP(call->rx_data_post, ==, 0); 1146 call->rx_data_post = 1; 1147 read_lock_bh(&call->state_lock); 1148 if (call->state < RXRPC_CALL_COMPLETE) 1149 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events); 1150 read_unlock_bh(&call->state_lock); 1151 } 1152 1153 /* drain the out of sequence received packet queue into the packet Rx 1154 * queue */ 1155 if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) { 1156 while (call->rx_data_post == call->rx_first_oos) 1157 if (rxrpc_drain_rx_oos_queue(call) < 0) 1158 break; 1159 goto maybe_reschedule; 1160 } 1161 1162 /* other events may have been raised since we started checking */ 1163 goto maybe_reschedule; 1164 1165send_ACK_with_skew: 1166 ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) - 1167 ntohl(ack.serial)); 1168send_ACK: 1169 mtu = call->conn->trans->peer->if_mtu; 1170 mtu -= call->conn->trans->peer->hdrsize; 1171 ackinfo.maxMTU = htonl(mtu); 1172 ackinfo.rwind = htonl(32); 1173 1174 /* permit the peer to send us jumbo packets if it wants to */ 1175 ackinfo.rxMTU = htonl(5692); 1176 ackinfo.jumbo_max = htonl(4); 1177 1178 hdr.serial = htonl(atomic_inc_return(&call->conn->serial)); 1179 _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", 1180 ntohl(hdr.serial), 1181 ntohs(ack.maxSkew), 1182 ntohl(ack.firstPacket), 1183 ntohl(ack.previousPacket), 1184 ntohl(ack.serial), 1185 rxrpc_acks[ack.reason], 1186 ack.nAcks); 1187 1188 del_timer_sync(&call->ack_timer); 1189 if (ack.nAcks > 0) 1190 set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags); 1191 goto send_message_2; 1192 1193send_message: 1194 _debug("send message"); 1195 1196 hdr.serial = htonl(atomic_inc_return(&call->conn->serial)); 1197 _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial)); 1198send_message_2: 1199 1200 len = iov[0].iov_len; 1201 ioc = 1; 1202 if (iov[4].iov_len) { 1203 ioc = 5; 1204 len += iov[4].iov_len; 1205 len += iov[3].iov_len; 1206 len += iov[2].iov_len; 1207 len += iov[1].iov_len; 1208 } else if (iov[3].iov_len) { 1209 ioc = 4; 1210 len += iov[3].iov_len; 1211 len += iov[2].iov_len; 1212 len += iov[1].iov_len; 1213 } else if (iov[2].iov_len) { 1214 ioc = 3; 1215 len += iov[2].iov_len; 1216 len += iov[1].iov_len; 1217 } else if (iov[1].iov_len) { 1218 ioc = 2; 1219 len += iov[1].iov_len; 1220 } 1221 1222 ret = kernel_sendmsg(call->conn->trans->local->socket, 1223 &msg, iov, ioc, len); 1224 if (ret < 0) { 1225 _debug("sendmsg failed: %d", ret); 1226 read_lock_bh(&call->state_lock); 1227 if (call->state < RXRPC_CALL_DEAD) 1228 rxrpc_queue_call(call); 1229 read_unlock_bh(&call->state_lock); 1230 goto error; 1231 } 1232 1233 switch (genbit) { 1234 case RXRPC_CALL_ABORT: 1235 clear_bit(genbit, &call->events); 1236 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events); 1237 goto kill_ACKs; 1238 1239 case RXRPC_CALL_ACK_FINAL: 1240 write_lock_bh(&call->state_lock); 1241 if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK) 1242 call->state = RXRPC_CALL_COMPLETE; 1243 write_unlock_bh(&call->state_lock); 1244 goto kill_ACKs; 1245 1246 default: 1247 clear_bit(genbit, &call->events); 1248 switch (call->state) { 1249 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 1250 case RXRPC_CALL_CLIENT_RECV_REPLY: 1251 case RXRPC_CALL_SERVER_RECV_REQUEST: 1252 case RXRPC_CALL_SERVER_ACK_REQUEST: 1253 _debug("start ACK timer"); 1254 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 1255 call->ackr_serial, false); 1256 default: 1257 break; 1258 } 1259 goto maybe_reschedule; 1260 } 1261 1262kill_ACKs: 1263 del_timer_sync(&call->ack_timer); 1264 if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events)) 1265 rxrpc_put_call(call); 1266 clear_bit(RXRPC_CALL_ACK, &call->events); 1267 1268maybe_reschedule: 1269 if (call->events || !skb_queue_empty(&call->rx_queue)) { 1270 read_lock_bh(&call->state_lock); 1271 if (call->state < RXRPC_CALL_DEAD) 1272 rxrpc_queue_call(call); 1273 read_unlock_bh(&call->state_lock); 1274 } 1275 1276 /* don't leave aborted connections on the accept queue */ 1277 if (call->state >= RXRPC_CALL_COMPLETE && 1278 !list_empty(&call->accept_link)) { 1279 _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }", 1280 call, call->events, call->flags, 1281 ntohl(call->conn->cid)); 1282 1283 read_lock_bh(&call->state_lock); 1284 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 1285 !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) 1286 rxrpc_queue_call(call); 1287 read_unlock_bh(&call->state_lock); 1288 } 1289 1290error: 1291 clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags); 1292 kfree(acks); 1293 1294 /* because we don't want two CPUs both processing the work item for one 1295 * call at the same time, we use a flag to note when it's busy; however 1296 * this means there's a race between clearing the flag and setting the 1297 * work pending bit and the work item being processed again */ 1298 if (call->events && !work_pending(&call->processor)) { 1299 _debug("jumpstart %x", ntohl(call->conn->cid)); 1300 rxrpc_queue_call(call); 1301 } 1302 1303 _leave(""); 1304 return; 1305 1306no_mem: 1307 _debug("out of memory"); 1308 goto maybe_reschedule; 1309} 1310