1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Processing of received RxRPC packets 3 * 4 * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include "ar-internal.h" 11 12 /* Override priority when generating ACKs for received DATA */ 13 static const u8 rxrpc_ack_priority[RXRPC_ACK__INVALID] = { 14 [RXRPC_ACK_IDLE] = 1, 15 [RXRPC_ACK_DELAY] = 2, 16 [RXRPC_ACK_REQUESTED] = 3, 17 [RXRPC_ACK_DUPLICATE] = 4, 18 [RXRPC_ACK_EXCEEDS_WINDOW] = 5, 19 [RXRPC_ACK_NOSPACE] = 6, 20 [RXRPC_ACK_OUT_OF_SEQUENCE] = 7, 21 }; 22 23 static void rxrpc_proto_abort(struct rxrpc_call *call, rxrpc_seq_t seq, 24 enum rxrpc_abort_reason why) 25 { 26 rxrpc_abort_call(call, seq, RX_PROTOCOL_ERROR, -EBADMSG, why); 27 } 28 29 /* 30 * Do TCP-style congestion management [RFC5681]. 31 */ 32 static void rxrpc_congestion_management(struct rxrpc_call *call, 33 struct rxrpc_ack_summary *summary) 34 { 35 summary->change = rxrpc_cong_no_change; 36 summary->in_flight = rxrpc_tx_in_flight(call); 37 38 if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) { 39 summary->retrans_timeo = true; 40 call->cong_ssthresh = umax(summary->in_flight / 2, 2); 41 call->cong_cwnd = 1; 42 if (call->cong_cwnd >= call->cong_ssthresh && 43 call->cong_ca_state == RXRPC_CA_SLOW_START) { 44 call->cong_ca_state = RXRPC_CA_CONGEST_AVOIDANCE; 45 call->cong_tstamp = call->acks_latest_ts; 46 call->cong_cumul_acks = 0; 47 } 48 } 49 50 call->cong_cumul_acks += summary->nr_new_sacks; 51 call->cong_cumul_acks += summary->nr_new_hacks; 52 if (call->cong_cumul_acks > 255) 53 call->cong_cumul_acks = 255; 54 55 switch (call->cong_ca_state) { 56 case RXRPC_CA_SLOW_START: 57 if (call->acks_nr_snacks > 0) 58 goto packet_loss_detected; 59 if (call->cong_cumul_acks > 0) 60 call->cong_cwnd += 1; 61 if (call->cong_cwnd >= call->cong_ssthresh) { 62 call->cong_ca_state = RXRPC_CA_CONGEST_AVOIDANCE; 63 call->cong_tstamp = call->acks_latest_ts; 64 } 65 goto out; 66 67 case RXRPC_CA_CONGEST_AVOIDANCE: 68 if (call->acks_nr_snacks > 0) 69 goto packet_loss_detected; 70 71 /* We analyse the number of packets that get ACK'd per RTT 72 * period and increase the window if we managed to fill it. 73 */ 74 if (call->rtt_count == 0) 75 goto out; 76 if (ktime_before(call->acks_latest_ts, 77 ktime_add_us(call->cong_tstamp, 78 call->srtt_us >> 3))) 79 goto out_no_clear_ca; 80 summary->change = rxrpc_cong_rtt_window_end; 81 call->cong_tstamp = call->acks_latest_ts; 82 if (call->cong_cumul_acks >= call->cong_cwnd) 83 call->cong_cwnd++; 84 goto out; 85 86 case RXRPC_CA_PACKET_LOSS: 87 if (call->acks_nr_snacks == 0) 88 goto resume_normality; 89 90 if (summary->new_low_snack) { 91 summary->change = rxrpc_cong_new_low_nack; 92 call->cong_dup_acks = 1; 93 if (call->cong_extra > 1) 94 call->cong_extra = 1; 95 goto send_extra_data; 96 } 97 98 call->cong_dup_acks++; 99 if (call->cong_dup_acks < 3) 100 goto send_extra_data; 101 102 summary->change = rxrpc_cong_begin_retransmission; 103 call->cong_ca_state = RXRPC_CA_FAST_RETRANSMIT; 104 call->cong_ssthresh = umax(summary->in_flight / 2, 2); 105 call->cong_cwnd = call->cong_ssthresh + 3; 106 call->cong_extra = 0; 107 call->cong_dup_acks = 0; 108 summary->need_retransmit = true; 109 summary->in_fast_or_rto_recovery = true; 110 goto out; 111 112 case RXRPC_CA_FAST_RETRANSMIT: 113 rxrpc_tlp_init(call); 114 summary->in_fast_or_rto_recovery = true; 115 if (!summary->new_low_snack) { 116 if (summary->nr_new_sacks == 0) 117 call->cong_cwnd += 1; 118 call->cong_dup_acks++; 119 if (call->cong_dup_acks == 2) { 120 summary->change = rxrpc_cong_retransmit_again; 121 call->cong_dup_acks = 0; 122 summary->need_retransmit = true; 123 } 124 } else { 125 summary->change = rxrpc_cong_progress; 126 call->cong_cwnd = call->cong_ssthresh; 127 if (call->acks_nr_snacks == 0) { 128 summary->exiting_fast_or_rto_recovery = true; 129 goto resume_normality; 130 } 131 } 132 goto out; 133 134 default: 135 BUG(); 136 goto out; 137 } 138 139 resume_normality: 140 summary->change = rxrpc_cong_cleared_nacks; 141 call->cong_dup_acks = 0; 142 call->cong_extra = 0; 143 call->cong_tstamp = call->acks_latest_ts; 144 if (call->cong_cwnd < call->cong_ssthresh) 145 call->cong_ca_state = RXRPC_CA_SLOW_START; 146 else 147 call->cong_ca_state = RXRPC_CA_CONGEST_AVOIDANCE; 148 out: 149 call->cong_cumul_acks = 0; 150 out_no_clear_ca: 151 if (call->cong_cwnd >= RXRPC_TX_MAX_WINDOW) 152 call->cong_cwnd = RXRPC_TX_MAX_WINDOW; 153 trace_rxrpc_congest(call, summary); 154 return; 155 156 packet_loss_detected: 157 summary->change = rxrpc_cong_saw_nack; 158 call->cong_ca_state = RXRPC_CA_PACKET_LOSS; 159 call->cong_dup_acks = 0; 160 goto send_extra_data; 161 162 send_extra_data: 163 /* Send some previously unsent DATA if we have some to advance the ACK 164 * state. 165 */ 166 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) || 167 call->acks_nr_sacks != call->tx_top - call->tx_bottom) { 168 call->cong_extra++; 169 wake_up(&call->waitq); 170 } 171 goto out_no_clear_ca; 172 } 173 174 /* 175 * Degrade the congestion window if we haven't transmitted a packet for >1RTT. 176 */ 177 void rxrpc_congestion_degrade(struct rxrpc_call *call) 178 { 179 ktime_t rtt, now, time_since; 180 181 if (call->cong_ca_state != RXRPC_CA_SLOW_START && 182 call->cong_ca_state != RXRPC_CA_CONGEST_AVOIDANCE) 183 return; 184 if (__rxrpc_call_state(call) == RXRPC_CALL_CLIENT_AWAIT_REPLY) 185 return; 186 187 rtt = ns_to_ktime(call->srtt_us * (NSEC_PER_USEC / 8)); 188 now = ktime_get_real(); 189 time_since = ktime_sub(now, call->tx_last_sent); 190 if (ktime_before(time_since, rtt)) 191 return; 192 193 trace_rxrpc_reset_cwnd(call, time_since, rtt); 194 rxrpc_inc_stat(call->rxnet, stat_tx_data_cwnd_reset); 195 call->tx_last_sent = now; 196 call->cong_ca_state = RXRPC_CA_SLOW_START; 197 call->cong_ssthresh = umax(call->cong_ssthresh, call->cong_cwnd * 3 / 4); 198 call->cong_cwnd = umax(call->cong_cwnd / 2, RXRPC_MIN_CWND); 199 } 200 201 /* 202 * Add an RTT sample derived from an ACK'd DATA packet. 203 */ 204 static void rxrpc_add_data_rtt_sample(struct rxrpc_call *call, 205 struct rxrpc_ack_summary *summary, 206 struct rxrpc_txqueue *tq, 207 int ix) 208 { 209 ktime_t xmit_ts = ktime_add_us(tq->xmit_ts_base, tq->segment_xmit_ts[ix]); 210 211 rxrpc_call_add_rtt(call, rxrpc_rtt_rx_data_ack, -1, 212 summary->acked_serial, summary->ack_serial, 213 xmit_ts, call->acks_latest_ts); 214 __clear_bit(ix, &tq->rtt_samples); /* Prevent repeat RTT sample */ 215 } 216 217 /* 218 * Apply a hard ACK by advancing the Tx window. 219 */ 220 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, 221 struct rxrpc_ack_summary *summary) 222 { 223 struct rxrpc_txqueue *tq = call->tx_queue; 224 rxrpc_seq_t seq = call->tx_bottom + 1; 225 bool rot_last = false, trace = false; 226 227 _enter("%x,%x", call->tx_bottom, to); 228 229 trace_rxrpc_tx_rotate(call, seq, to); 230 trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate); 231 232 if (call->acks_lowest_nak == call->tx_bottom) { 233 call->acks_lowest_nak = to; 234 } else if (after(to, call->acks_lowest_nak)) { 235 summary->new_low_snack = true; 236 call->acks_lowest_nak = to; 237 } 238 239 /* We may have a left over fully-consumed buffer at the front that we 240 * couldn't drop before (rotate_and_keep below). 241 */ 242 if (seq == call->tx_qbase + RXRPC_NR_TXQUEUE) { 243 call->tx_qbase += RXRPC_NR_TXQUEUE; 244 call->tx_queue = tq->next; 245 trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_free); 246 kfree(tq); 247 tq = call->tx_queue; 248 } 249 250 do { 251 unsigned int ix = seq - call->tx_qbase; 252 253 _debug("tq=%x seq=%x i=%d f=%x", tq->qbase, seq, ix, tq->bufs[ix]->flags); 254 if (tq->bufs[ix]->flags & RXRPC_LAST_PACKET) { 255 set_bit(RXRPC_CALL_TX_LAST, &call->flags); 256 rot_last = true; 257 } 258 259 if (summary->acked_serial == tq->segment_serial[ix] && 260 test_bit(ix, &tq->rtt_samples)) 261 rxrpc_add_data_rtt_sample(call, summary, tq, ix); 262 263 if (ix == tq->nr_reported_acks) { 264 /* Packet directly hard ACK'd. */ 265 tq->nr_reported_acks++; 266 rxrpc_input_rack_one(call, summary, tq, ix); 267 if (seq == call->tlp_seq) 268 summary->tlp_probe_acked = true; 269 summary->nr_new_hacks++; 270 __set_bit(ix, &tq->segment_acked); 271 trace_rxrpc_rotate(call, tq, summary, seq, rxrpc_rotate_trace_hack); 272 } else if (test_bit(ix, &tq->segment_acked)) { 273 /* Soft ACK -> hard ACK. */ 274 call->acks_nr_sacks--; 275 trace_rxrpc_rotate(call, tq, summary, seq, rxrpc_rotate_trace_sack); 276 } else { 277 /* Soft NAK -> hard ACK. */ 278 call->acks_nr_snacks--; 279 rxrpc_input_rack_one(call, summary, tq, ix); 280 if (seq == call->tlp_seq) 281 summary->tlp_probe_acked = true; 282 summary->nr_new_hacks++; 283 __set_bit(ix, &tq->segment_acked); 284 trace_rxrpc_rotate(call, tq, summary, seq, rxrpc_rotate_trace_snak); 285 } 286 287 call->tx_nr_sent--; 288 if (__test_and_clear_bit(ix, &tq->segment_lost)) 289 call->tx_nr_lost--; 290 if (__test_and_clear_bit(ix, &tq->segment_retransmitted)) 291 call->tx_nr_resent--; 292 __clear_bit(ix, &tq->ever_retransmitted); 293 294 rxrpc_put_txbuf(tq->bufs[ix], rxrpc_txbuf_put_rotated); 295 tq->bufs[ix] = NULL; 296 297 WRITE_ONCE(call->tx_bottom, seq); 298 trace_rxrpc_txqueue(call, (rot_last ? 299 rxrpc_txqueue_rotate_last : 300 rxrpc_txqueue_rotate)); 301 302 seq++; 303 trace = true; 304 if (!(seq & RXRPC_TXQ_MASK)) { 305 trace_rxrpc_rack_update(call, summary); 306 trace = false; 307 prefetch(tq->next); 308 if (tq != call->tx_qtail) { 309 call->tx_qbase += RXRPC_NR_TXQUEUE; 310 call->tx_queue = tq->next; 311 trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_free); 312 kfree(tq); 313 tq = call->tx_queue; 314 } else { 315 trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_keep); 316 tq = NULL; 317 break; 318 } 319 } 320 321 } while (before_eq(seq, to)); 322 323 if (trace) 324 trace_rxrpc_rack_update(call, summary); 325 326 if (rot_last) { 327 set_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags); 328 if (tq) { 329 trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_free); 330 kfree(tq); 331 call->tx_queue = NULL; 332 } 333 } 334 335 _debug("%x,%x,%x,%d", to, call->tx_bottom, call->tx_top, rot_last); 336 337 wake_up(&call->waitq); 338 return rot_last; 339 } 340 341 /* 342 * End the transmission phase of a call. 343 * 344 * This occurs when we get an ACKALL packet, the first DATA packet of a reply, 345 * or a final ACK packet. 346 */ 347 static void rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, 348 enum rxrpc_abort_reason abort_why) 349 { 350 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags)); 351 352 call->rack_timer_mode = RXRPC_CALL_RACKTIMER_OFF; 353 call->rack_timo_at = KTIME_MAX; 354 trace_rxrpc_rack_timer(call, 0, false); 355 trace_rxrpc_timer_can(call, rxrpc_timer_trace_rack_off + call->rack_timer_mode); 356 357 switch (__rxrpc_call_state(call)) { 358 case RXRPC_CALL_CLIENT_SEND_REQUEST: 359 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 360 if (reply_begun) { 361 rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_RECV_REPLY); 362 trace_rxrpc_txqueue(call, rxrpc_txqueue_end); 363 break; 364 } 365 366 rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_REPLY); 367 trace_rxrpc_txqueue(call, rxrpc_txqueue_await_reply); 368 break; 369 370 case RXRPC_CALL_SERVER_AWAIT_ACK: 371 rxrpc_call_completed(call); 372 trace_rxrpc_txqueue(call, rxrpc_txqueue_end); 373 break; 374 375 default: 376 kdebug("end_tx %s", rxrpc_call_states[__rxrpc_call_state(call)]); 377 rxrpc_proto_abort(call, call->tx_top, abort_why); 378 break; 379 } 380 } 381 382 /* 383 * Begin the reply reception phase of a call. 384 */ 385 static bool rxrpc_receiving_reply(struct rxrpc_call *call) 386 { 387 struct rxrpc_ack_summary summary = { 0 }; 388 rxrpc_seq_t top = READ_ONCE(call->tx_top); 389 390 if (call->ackr_reason) { 391 call->delay_ack_at = KTIME_MAX; 392 trace_rxrpc_timer_can(call, rxrpc_timer_trace_delayed_ack); 393 } 394 395 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 396 if (!rxrpc_rotate_tx_window(call, top, &summary)) { 397 rxrpc_proto_abort(call, top, rxrpc_eproto_early_reply); 398 return false; 399 } 400 } 401 402 rxrpc_end_tx_phase(call, true, rxrpc_eproto_unexpected_reply); 403 return true; 404 } 405 406 /* 407 * End the packet reception phase. 408 */ 409 static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial) 410 { 411 rxrpc_seq_t whigh = READ_ONCE(call->rx_highest_seq); 412 413 _enter("%d,%s", call->debug_id, rxrpc_call_states[__rxrpc_call_state(call)]); 414 415 trace_rxrpc_receive(call, rxrpc_receive_end, 0, whigh); 416 417 switch (__rxrpc_call_state(call)) { 418 case RXRPC_CALL_CLIENT_RECV_REPLY: 419 rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_terminal_ack); 420 rxrpc_call_completed(call); 421 break; 422 423 case RXRPC_CALL_SERVER_RECV_REQUEST: 424 rxrpc_set_call_state(call, RXRPC_CALL_SERVER_ACK_REQUEST); 425 call->expect_req_by = KTIME_MAX; 426 rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_processing_op); 427 break; 428 429 default: 430 break; 431 } 432 } 433 434 static void rxrpc_input_update_ack_window(struct rxrpc_call *call, 435 rxrpc_seq_t window, rxrpc_seq_t wtop) 436 { 437 call->ackr_window = window; 438 call->ackr_wtop = wtop; 439 } 440 441 /* 442 * Push a DATA packet onto the Rx queue. 443 */ 444 static void rxrpc_input_queue_data(struct rxrpc_call *call, struct sk_buff *skb, 445 rxrpc_seq_t window, rxrpc_seq_t wtop, 446 enum rxrpc_receive_trace why) 447 { 448 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 449 bool last = sp->hdr.flags & RXRPC_LAST_PACKET; 450 451 spin_lock_irq(&call->recvmsg_queue.lock); 452 453 __skb_queue_tail(&call->recvmsg_queue, skb); 454 rxrpc_input_update_ack_window(call, window, wtop); 455 trace_rxrpc_receive(call, last ? why + 1 : why, sp->hdr.serial, sp->hdr.seq); 456 if (last) 457 /* Change the state inside the lock so that recvmsg syncs 458 * correctly with it and using sendmsg() to send a reply 459 * doesn't race. 460 */ 461 rxrpc_end_rx_phase(call, sp->hdr.serial); 462 463 spin_unlock_irq(&call->recvmsg_queue.lock); 464 } 465 466 /* 467 * Process a DATA packet. 468 */ 469 static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb, 470 bool *_notify, rxrpc_serial_t *_ack_serial, int *_ack_reason) 471 { 472 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 473 struct sk_buff *oos; 474 rxrpc_serial_t serial = sp->hdr.serial; 475 unsigned int sack = call->ackr_sack_base; 476 rxrpc_seq_t window = call->ackr_window; 477 rxrpc_seq_t wtop = call->ackr_wtop; 478 rxrpc_seq_t wlimit = window + call->rx_winsize - 1; 479 rxrpc_seq_t seq = sp->hdr.seq; 480 bool last = sp->hdr.flags & RXRPC_LAST_PACKET; 481 int ack_reason = -1; 482 483 rxrpc_inc_stat(call->rxnet, stat_rx_data); 484 if (sp->hdr.flags & RXRPC_REQUEST_ACK) 485 rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack); 486 if (sp->hdr.flags & RXRPC_JUMBO_PACKET) 487 rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo); 488 489 if (last) { 490 if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) && 491 seq + 1 != wtop) 492 return rxrpc_proto_abort(call, seq, rxrpc_eproto_different_last); 493 } else { 494 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 495 after_eq(seq, wtop)) { 496 pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n", 497 call->debug_id, seq, window, wtop, wlimit); 498 return rxrpc_proto_abort(call, seq, rxrpc_eproto_data_after_last); 499 } 500 } 501 502 if (after(seq, call->rx_highest_seq)) 503 call->rx_highest_seq = seq; 504 505 trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags); 506 507 if (before(seq, window)) { 508 ack_reason = RXRPC_ACK_DUPLICATE; 509 goto send_ack; 510 } 511 if (after(seq, wlimit)) { 512 ack_reason = RXRPC_ACK_EXCEEDS_WINDOW; 513 goto send_ack; 514 } 515 516 /* Queue the packet. */ 517 if (seq == window) { 518 if (sp->hdr.flags & RXRPC_REQUEST_ACK) 519 ack_reason = RXRPC_ACK_REQUESTED; 520 /* Send an immediate ACK if we fill in a hole */ 521 else if (!skb_queue_empty(&call->rx_oos_queue)) 522 ack_reason = RXRPC_ACK_DELAY; 523 524 window++; 525 if (after(window, wtop)) { 526 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_none); 527 wtop = window; 528 } else { 529 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_advance); 530 sack = (sack + 1) % RXRPC_SACK_SIZE; 531 } 532 533 534 rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg); 535 536 rxrpc_input_queue_data(call, skb, window, wtop, rxrpc_receive_queue); 537 *_notify = true; 538 539 while ((oos = skb_peek(&call->rx_oos_queue))) { 540 struct rxrpc_skb_priv *osp = rxrpc_skb(oos); 541 542 if (after(osp->hdr.seq, window)) 543 break; 544 545 __skb_unlink(oos, &call->rx_oos_queue); 546 last = osp->hdr.flags & RXRPC_LAST_PACKET; 547 seq = osp->hdr.seq; 548 call->ackr_sack_table[sack] = 0; 549 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_fill); 550 sack = (sack + 1) % RXRPC_SACK_SIZE; 551 552 window++; 553 rxrpc_input_queue_data(call, oos, window, wtop, 554 rxrpc_receive_queue_oos); 555 } 556 557 call->ackr_sack_base = sack; 558 } else { 559 unsigned int slot; 560 561 ack_reason = RXRPC_ACK_OUT_OF_SEQUENCE; 562 563 slot = seq - window; 564 sack = (sack + slot) % RXRPC_SACK_SIZE; 565 566 if (call->ackr_sack_table[sack % RXRPC_SACK_SIZE]) { 567 ack_reason = RXRPC_ACK_DUPLICATE; 568 goto send_ack; 569 } 570 571 call->ackr_sack_table[sack % RXRPC_SACK_SIZE] |= 1; 572 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_oos); 573 574 if (after(seq + 1, wtop)) { 575 wtop = seq + 1; 576 rxrpc_input_update_ack_window(call, window, wtop); 577 } 578 579 skb_queue_walk(&call->rx_oos_queue, oos) { 580 struct rxrpc_skb_priv *osp = rxrpc_skb(oos); 581 582 if (after(osp->hdr.seq, seq)) { 583 rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos); 584 __skb_queue_before(&call->rx_oos_queue, oos, skb); 585 goto oos_queued; 586 } 587 } 588 589 rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos); 590 __skb_queue_tail(&call->rx_oos_queue, skb); 591 oos_queued: 592 trace_rxrpc_receive(call, last ? rxrpc_receive_oos_last : rxrpc_receive_oos, 593 sp->hdr.serial, sp->hdr.seq); 594 } 595 596 send_ack: 597 if (ack_reason >= 0) { 598 if (rxrpc_ack_priority[ack_reason] > rxrpc_ack_priority[*_ack_reason]) { 599 *_ack_serial = serial; 600 *_ack_reason = ack_reason; 601 } else if (rxrpc_ack_priority[ack_reason] == rxrpc_ack_priority[*_ack_reason] && 602 ack_reason == RXRPC_ACK_REQUESTED) { 603 *_ack_serial = serial; 604 *_ack_reason = ack_reason; 605 } 606 } 607 } 608 609 /* 610 * Split a jumbo packet and file the bits separately. 611 */ 612 static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb) 613 { 614 struct rxrpc_jumbo_header jhdr; 615 struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp; 616 struct sk_buff *jskb; 617 rxrpc_serial_t ack_serial = 0; 618 unsigned int offset = sizeof(struct rxrpc_wire_header); 619 unsigned int len = skb->len - offset; 620 bool notify = false; 621 int ack_reason = 0, count = 1, stat_ix; 622 623 while (sp->hdr.flags & RXRPC_JUMBO_PACKET) { 624 if (len < RXRPC_JUMBO_SUBPKTLEN) 625 goto protocol_error; 626 if (sp->hdr.flags & RXRPC_LAST_PACKET) 627 goto protocol_error; 628 if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN, 629 &jhdr, sizeof(jhdr)) < 0) 630 goto protocol_error; 631 632 jskb = skb_clone(skb, GFP_NOFS); 633 if (!jskb) { 634 kdebug("couldn't clone"); 635 return false; 636 } 637 rxrpc_new_skb(jskb, rxrpc_skb_new_jumbo_subpacket); 638 jsp = rxrpc_skb(jskb); 639 jsp->offset = offset; 640 jsp->len = RXRPC_JUMBO_DATALEN; 641 rxrpc_input_data_one(call, jskb, ¬ify, &ack_serial, &ack_reason); 642 rxrpc_free_skb(jskb, rxrpc_skb_put_jumbo_subpacket); 643 644 sp->hdr.flags = jhdr.flags; 645 sp->hdr._rsvd = ntohs(jhdr._rsvd); 646 sp->hdr.seq++; 647 sp->hdr.serial++; 648 offset += RXRPC_JUMBO_SUBPKTLEN; 649 len -= RXRPC_JUMBO_SUBPKTLEN; 650 count++; 651 } 652 653 sp->offset = offset; 654 sp->len = len; 655 rxrpc_input_data_one(call, skb, ¬ify, &ack_serial, &ack_reason); 656 657 stat_ix = umin(count, ARRAY_SIZE(call->rxnet->stat_rx_jumbo)) - 1; 658 atomic_inc(&call->rxnet->stat_rx_jumbo[stat_ix]); 659 660 if (ack_reason > 0) { 661 rxrpc_send_ACK(call, ack_reason, ack_serial, 662 rxrpc_propose_ack_input_data); 663 } else { 664 call->ackr_nr_unacked++; 665 rxrpc_propose_delay_ACK(call, sp->hdr.serial, 666 rxrpc_propose_ack_input_data); 667 } 668 if (notify && !test_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags)) { 669 trace_rxrpc_notify_socket(call->debug_id, sp->hdr.serial); 670 rxrpc_notify_socket(call); 671 } 672 return true; 673 674 protocol_error: 675 return false; 676 } 677 678 /* 679 * Process a DATA packet, adding the packet to the Rx ring. The caller's 680 * packet ref must be passed on or discarded. 681 */ 682 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb) 683 { 684 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 685 rxrpc_serial_t serial = sp->hdr.serial; 686 rxrpc_seq_t seq0 = sp->hdr.seq; 687 688 _enter("{%x,%x,%x},{%u,%x}", 689 call->ackr_window, call->ackr_wtop, call->rx_highest_seq, 690 skb->len, seq0); 691 692 if (__rxrpc_call_is_complete(call)) 693 return; 694 695 switch (__rxrpc_call_state(call)) { 696 case RXRPC_CALL_CLIENT_SEND_REQUEST: 697 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 698 /* Received data implicitly ACKs all of the request 699 * packets we sent when we're acting as a client. 700 */ 701 if (!rxrpc_receiving_reply(call)) 702 goto out_notify; 703 break; 704 705 case RXRPC_CALL_SERVER_RECV_REQUEST: { 706 unsigned long timo = READ_ONCE(call->next_req_timo); 707 708 if (timo) { 709 ktime_t delay = ms_to_ktime(timo); 710 711 call->expect_req_by = ktime_add(ktime_get_real(), delay); 712 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_idle); 713 } 714 break; 715 } 716 717 default: 718 break; 719 } 720 721 if (!rxrpc_input_split_jumbo(call, skb)) { 722 rxrpc_proto_abort(call, sp->hdr.seq, rxrpc_badmsg_bad_jumbo); 723 goto out_notify; 724 } 725 return; 726 727 out_notify: 728 trace_rxrpc_notify_socket(call->debug_id, serial); 729 rxrpc_notify_socket(call); 730 _leave(" [queued]"); 731 } 732 733 /* 734 * See if there's a cached RTT probe to complete. 735 */ 736 static void rxrpc_complete_rtt_probe(struct rxrpc_call *call, 737 ktime_t resp_time, 738 rxrpc_serial_t acked_serial, 739 rxrpc_serial_t ack_serial, 740 enum rxrpc_rtt_rx_trace type) 741 { 742 rxrpc_serial_t orig_serial; 743 unsigned long avail; 744 ktime_t sent_at; 745 bool matched = false; 746 int i; 747 748 avail = READ_ONCE(call->rtt_avail); 749 smp_rmb(); /* Read avail bits before accessing data. */ 750 751 for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) { 752 if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail)) 753 continue; 754 755 sent_at = call->rtt_sent_at[i]; 756 orig_serial = call->rtt_serial[i]; 757 758 if (orig_serial == acked_serial) { 759 clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 760 smp_mb(); /* Read data before setting avail bit */ 761 set_bit(i, &call->rtt_avail); 762 rxrpc_call_add_rtt(call, type, i, acked_serial, ack_serial, 763 sent_at, resp_time); 764 matched = true; 765 } 766 767 /* If a later serial is being acked, then mark this slot as 768 * being available. 769 */ 770 if (after(acked_serial, orig_serial)) { 771 trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i, 772 orig_serial, acked_serial, 0, 0, 0); 773 clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 774 smp_wmb(); 775 set_bit(i, &call->rtt_avail); 776 } 777 } 778 779 if (!matched) 780 trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0, 0); 781 } 782 783 /* 784 * Process the extra information that may be appended to an ACK packet 785 */ 786 static void rxrpc_input_ack_trailer(struct rxrpc_call *call, struct sk_buff *skb, 787 struct rxrpc_acktrailer *trailer) 788 { 789 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 790 struct rxrpc_peer *peer = call->peer; 791 unsigned int max_data, capacity; 792 bool wake = false; 793 u32 max_mtu = ntohl(trailer->maxMTU); 794 //u32 if_mtu = ntohl(trailer->ifMTU); 795 u32 rwind = ntohl(trailer->rwind); 796 u32 jumbo_max = ntohl(trailer->jumbo_max); 797 798 if (rwind > RXRPC_TX_MAX_WINDOW) 799 rwind = RXRPC_TX_MAX_WINDOW; 800 if (call->tx_winsize != rwind) { 801 if (rwind > call->tx_winsize) 802 wake = true; 803 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake); 804 call->tx_winsize = rwind; 805 } 806 807 max_mtu = clamp(max_mtu, 500, 65535); 808 peer->ackr_max_data = max_mtu; 809 810 if (max_mtu < peer->max_data) { 811 trace_rxrpc_pmtud_reduce(peer, sp->hdr.serial, max_mtu, 812 rxrpc_pmtud_reduce_ack); 813 write_seqcount_begin(&peer->mtu_lock); 814 peer->max_data = max_mtu; 815 write_seqcount_end(&peer->mtu_lock); 816 } 817 818 max_data = umin(max_mtu, peer->max_data); 819 capacity = max_data; 820 capacity += sizeof(struct rxrpc_jumbo_header); /* First subpacket has main hdr, not jumbo */ 821 capacity /= sizeof(struct rxrpc_jumbo_header) + RXRPC_JUMBO_DATALEN; 822 823 if (jumbo_max == 0) { 824 /* The peer says it supports pmtu discovery */ 825 peer->ackr_adv_pmtud = true; 826 } else { 827 peer->ackr_adv_pmtud = false; 828 capacity = clamp(capacity, 1, jumbo_max); 829 } 830 831 call->tx_jumbo_max = capacity; 832 833 if (wake) 834 wake_up(&call->waitq); 835 } 836 837 #if defined(CONFIG_X86) && __GNUC__ && !defined(__clang__) 838 /* Clang doesn't support the %z constraint modifier */ 839 #define shiftr_adv_rotr(shift_from, rotate_into) ({ \ 840 asm(" shr%z1 %1\n" \ 841 " inc %0\n" \ 842 " rcr%z2 %2\n" \ 843 : "+d"(shift_from), "+m"(*(shift_from)), "+rm"(rotate_into) \ 844 ); \ 845 }) 846 #else 847 #define shiftr_adv_rotr(shift_from, rotate_into) ({ \ 848 typeof(rotate_into) __bit0 = *(shift_from) & 1; \ 849 *(shift_from) >>= 1; \ 850 shift_from++; \ 851 rotate_into >>= 1; \ 852 rotate_into |= __bit0 << (sizeof(rotate_into) * 8 - 1); \ 853 }) 854 #endif 855 856 /* 857 * Deal with RTT samples from soft ACKs. 858 */ 859 static void rxrpc_input_soft_rtt(struct rxrpc_call *call, 860 struct rxrpc_ack_summary *summary, 861 struct rxrpc_txqueue *tq) 862 { 863 for (int ix = 0; ix < RXRPC_NR_TXQUEUE; ix++) 864 if (summary->acked_serial == tq->segment_serial[ix]) 865 return rxrpc_add_data_rtt_sample(call, summary, tq, ix); 866 } 867 868 /* 869 * Process a batch of soft ACKs specific to a transmission queue segment. 870 */ 871 static void rxrpc_input_soft_ack_tq(struct rxrpc_call *call, 872 struct rxrpc_ack_summary *summary, 873 struct rxrpc_txqueue *tq, 874 unsigned long extracted_acks, 875 int nr_reported, 876 rxrpc_seq_t seq, 877 rxrpc_seq_t *lowest_nak) 878 { 879 unsigned long old_reported = 0, flipped, new_acks = 0; 880 unsigned long a_to_n, n_to_a = 0; 881 int new, a, n; 882 883 if (tq->nr_reported_acks > 0) 884 old_reported = ~0UL >> (RXRPC_NR_TXQUEUE - tq->nr_reported_acks); 885 886 _enter("{%x,%lx,%d},%lx,%d,%x", 887 tq->qbase, tq->segment_acked, tq->nr_reported_acks, 888 extracted_acks, nr_reported, seq); 889 890 _debug("[%x]", tq->qbase); 891 _debug("tq %16lx %u", tq->segment_acked, tq->nr_reported_acks); 892 _debug("sack %16lx %u", extracted_acks, nr_reported); 893 894 /* See how many previously logged ACKs/NAKs have flipped. */ 895 flipped = (tq->segment_acked ^ extracted_acks) & old_reported; 896 if (flipped) { 897 n_to_a = ~tq->segment_acked & flipped; /* Old NAK -> ACK */ 898 a_to_n = tq->segment_acked & flipped; /* Old ACK -> NAK */ 899 a = hweight_long(n_to_a); 900 n = hweight_long(a_to_n); 901 _debug("flip %16lx", flipped); 902 _debug("ntoa %16lx %d", n_to_a, a); 903 _debug("aton %16lx %d", a_to_n, n); 904 call->acks_nr_sacks += a - n; 905 call->acks_nr_snacks += n - a; 906 summary->nr_new_sacks += a; 907 summary->nr_new_snacks += n; 908 } 909 910 /* See how many new ACKs/NAKs have been acquired. */ 911 new = nr_reported - tq->nr_reported_acks; 912 if (new > 0) { 913 new_acks = extracted_acks & ~old_reported; 914 if (new_acks) { 915 a = hweight_long(new_acks); 916 n = new - a; 917 _debug("new_a %16lx new=%d a=%d n=%d", new_acks, new, a, n); 918 call->acks_nr_sacks += a; 919 call->acks_nr_snacks += n; 920 summary->nr_new_sacks += a; 921 summary->nr_new_snacks += n; 922 } else { 923 call->acks_nr_snacks += new; 924 summary->nr_new_snacks += new; 925 } 926 } 927 928 tq->nr_reported_acks = nr_reported; 929 tq->segment_acked = extracted_acks; 930 trace_rxrpc_apply_acks(call, tq); 931 932 if (extracted_acks != ~0UL) { 933 rxrpc_seq_t lowest = seq + ffz(extracted_acks); 934 935 if (before(lowest, *lowest_nak)) 936 *lowest_nak = lowest; 937 } 938 939 if (summary->acked_serial) 940 rxrpc_input_soft_rtt(call, summary, tq); 941 942 new_acks |= n_to_a; 943 if (new_acks) 944 rxrpc_input_rack(call, summary, tq, new_acks); 945 946 if (call->tlp_serial && 947 rxrpc_seq_in_txq(tq, call->tlp_seq) && 948 test_bit(call->tlp_seq - tq->qbase, &new_acks)) 949 summary->tlp_probe_acked = true; 950 } 951 952 /* 953 * Process individual soft ACKs. 954 * 955 * Each ACK in the array corresponds to one packet and can be either an ACK or 956 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 957 * packets that lie beyond the end of the ACK list are scheduled for resend by 958 * the timer on the basis that the peer might just not have processed them at 959 * the time the ACK was sent. 960 */ 961 static void rxrpc_input_soft_acks(struct rxrpc_call *call, 962 struct rxrpc_ack_summary *summary, 963 struct sk_buff *skb) 964 { 965 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 966 struct rxrpc_txqueue *tq = call->tx_queue; 967 unsigned long extracted = ~0UL; 968 unsigned int nr = 0; 969 rxrpc_seq_t seq = call->acks_hard_ack + 1; 970 rxrpc_seq_t lowest_nak = seq + sp->ack.nr_acks; 971 u8 *acks = skb->data + sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket); 972 973 _enter("%x,%x,%u", tq->qbase, seq, sp->ack.nr_acks); 974 975 while (after(seq, tq->qbase + RXRPC_NR_TXQUEUE - 1)) 976 tq = tq->next; 977 978 for (unsigned int i = 0; i < sp->ack.nr_acks; i++) { 979 /* Decant ACKs until we hit a txqueue boundary. */ 980 shiftr_adv_rotr(acks, extracted); 981 if (i == 256) { 982 acks -= i; 983 i = 0; 984 } 985 seq++; 986 nr++; 987 if ((seq & RXRPC_TXQ_MASK) != 0) 988 continue; 989 990 _debug("bound %16lx %u", extracted, nr); 991 992 rxrpc_input_soft_ack_tq(call, summary, tq, extracted, RXRPC_NR_TXQUEUE, 993 seq - RXRPC_NR_TXQUEUE, &lowest_nak); 994 extracted = ~0UL; 995 nr = 0; 996 tq = tq->next; 997 prefetch(tq); 998 } 999 1000 if (nr) { 1001 unsigned int nr_reported = seq & RXRPC_TXQ_MASK; 1002 1003 extracted >>= RXRPC_NR_TXQUEUE - nr_reported; 1004 _debug("tail %16lx %u", extracted, nr_reported); 1005 rxrpc_input_soft_ack_tq(call, summary, tq, extracted, nr_reported, 1006 seq & ~RXRPC_TXQ_MASK, &lowest_nak); 1007 } 1008 1009 /* We *can* have more nacks than we did - the peer is permitted to drop 1010 * packets it has soft-acked and re-request them. Further, it is 1011 * possible for the nack distribution to change whilst the number of 1012 * nacks stays the same or goes down. 1013 */ 1014 if (lowest_nak != call->acks_lowest_nak) { 1015 call->acks_lowest_nak = lowest_nak; 1016 summary->new_low_snack = true; 1017 } 1018 1019 _debug("summary A=%d+%d N=%d+%d", 1020 call->acks_nr_sacks, summary->nr_new_sacks, 1021 call->acks_nr_snacks, summary->nr_new_snacks); 1022 } 1023 1024 /* 1025 * Return true if the ACK is valid - ie. it doesn't appear to have regressed 1026 * with respect to the ack state conveyed by preceding ACKs. 1027 */ 1028 static bool rxrpc_is_ack_valid(struct rxrpc_call *call, 1029 rxrpc_seq_t hard_ack, rxrpc_seq_t prev_pkt) 1030 { 1031 rxrpc_seq_t base = READ_ONCE(call->acks_hard_ack); 1032 1033 if (after(hard_ack, base)) 1034 return true; /* The window advanced */ 1035 1036 if (before(hard_ack, base)) 1037 return false; /* firstPacket regressed */ 1038 1039 if (after_eq(prev_pkt, call->acks_prev_seq)) 1040 return true; /* previousPacket hasn't regressed. */ 1041 1042 /* Some rx implementations put a serial number in previousPacket. */ 1043 if (after(prev_pkt, base + call->tx_winsize)) 1044 return false; 1045 return true; 1046 } 1047 1048 /* 1049 * Process an ACK packet. 1050 * 1051 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 1052 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 1053 * 1054 * A hard-ACK means that a packet has been processed and may be discarded; a 1055 * soft-ACK means that the packet may be discarded and retransmission 1056 * requested. A phase is complete when all packets are hard-ACK'd. 1057 */ 1058 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb) 1059 { 1060 struct rxrpc_ack_summary summary = { 0 }; 1061 struct rxrpc_acktrailer trailer; 1062 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1063 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 1064 int nr_acks, offset, ioffset; 1065 1066 _enter(""); 1067 1068 offset = sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket); 1069 1070 summary.ack_serial = sp->hdr.serial; 1071 first_soft_ack = sp->ack.first_ack; 1072 prev_pkt = sp->ack.prev_ack; 1073 nr_acks = sp->ack.nr_acks; 1074 hard_ack = first_soft_ack - 1; 1075 summary.acked_serial = sp->ack.acked_serial; 1076 summary.ack_reason = (sp->ack.reason < RXRPC_ACK__INVALID ? 1077 sp->ack.reason : RXRPC_ACK__INVALID); 1078 1079 trace_rxrpc_rx_ack(call, sp); 1080 rxrpc_inc_stat(call->rxnet, stat_rx_acks[summary.ack_reason]); 1081 prefetch(call->tx_queue); 1082 1083 /* If we get an EXCEEDS_WINDOW ACK from the server, it probably 1084 * indicates that the client address changed due to NAT. The server 1085 * lost the call because it switched to a different peer. 1086 */ 1087 if (unlikely(summary.ack_reason == RXRPC_ACK_EXCEEDS_WINDOW) && 1088 hard_ack == 0 && 1089 prev_pkt == 0 && 1090 rxrpc_is_client_call(call)) { 1091 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1092 0, -ENETRESET); 1093 goto send_response; 1094 } 1095 1096 /* If we get an OUT_OF_SEQUENCE ACK from the server, that can also 1097 * indicate a change of address. However, we can retransmit the call 1098 * if we still have it buffered to the beginning. 1099 */ 1100 if (unlikely(summary.ack_reason == RXRPC_ACK_OUT_OF_SEQUENCE) && 1101 hard_ack == 0 && 1102 prev_pkt == 0 && 1103 call->tx_bottom == 0 && 1104 rxrpc_is_client_call(call)) { 1105 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1106 0, -ENETRESET); 1107 goto send_response; 1108 } 1109 1110 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 1111 if (!rxrpc_is_ack_valid(call, hard_ack, prev_pkt)) { 1112 trace_rxrpc_rx_discard_ack(call, summary.ack_serial, hard_ack, prev_pkt); 1113 goto send_response; /* Still respond if requested. */ 1114 } 1115 1116 trailer.maxMTU = 0; 1117 ioffset = offset + nr_acks + 3; 1118 if (skb->len >= ioffset + sizeof(trailer) && 1119 skb_copy_bits(skb, ioffset, &trailer, sizeof(trailer)) < 0) 1120 return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack_trailer); 1121 1122 if (nr_acks > 0) 1123 skb_condense(skb); 1124 1125 call->acks_latest_ts = ktime_get_real(); 1126 call->acks_hard_ack = hard_ack; 1127 call->acks_prev_seq = prev_pkt; 1128 1129 if (summary.acked_serial) { 1130 switch (summary.ack_reason) { 1131 case RXRPC_ACK_PING_RESPONSE: 1132 rxrpc_complete_rtt_probe(call, call->acks_latest_ts, 1133 summary.acked_serial, summary.ack_serial, 1134 rxrpc_rtt_rx_ping_response); 1135 break; 1136 default: 1137 if (after(summary.acked_serial, call->acks_highest_serial)) 1138 call->acks_highest_serial = summary.acked_serial; 1139 summary.rtt_sample_avail = true; 1140 break; 1141 } 1142 } 1143 1144 /* Parse rwind and mtu sizes if provided. */ 1145 if (trailer.maxMTU) 1146 rxrpc_input_ack_trailer(call, skb, &trailer); 1147 1148 if (hard_ack + 1 == 0) 1149 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_zero); 1150 1151 /* Ignore ACKs unless we are or have just been transmitting. */ 1152 switch (__rxrpc_call_state(call)) { 1153 case RXRPC_CALL_CLIENT_SEND_REQUEST: 1154 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 1155 case RXRPC_CALL_SERVER_SEND_REPLY: 1156 case RXRPC_CALL_SERVER_AWAIT_ACK: 1157 break; 1158 default: 1159 goto send_response; 1160 } 1161 1162 if (before(hard_ack, call->tx_bottom) || 1163 after(hard_ack, call->tx_top)) 1164 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_outside_window); 1165 if (nr_acks > call->tx_top - hard_ack) 1166 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_sack_overflow); 1167 1168 if (after(hard_ack, call->tx_bottom)) { 1169 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 1170 rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ack); 1171 goto send_response; 1172 } 1173 } 1174 1175 if (nr_acks > 0) { 1176 if (offset > (int)skb->len - nr_acks) 1177 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_short_sack); 1178 rxrpc_input_soft_acks(call, &summary, skb); 1179 } 1180 1181 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) && 1182 call->acks_nr_sacks == call->tx_top - hard_ack && 1183 rxrpc_is_client_call(call)) 1184 rxrpc_propose_ping(call, summary.ack_serial, 1185 rxrpc_propose_ack_ping_for_lost_reply); 1186 1187 /* Drive the congestion management algorithm first and then RACK-TLP as 1188 * the latter depends on the state/change in state in the former. 1189 */ 1190 rxrpc_congestion_management(call, &summary); 1191 rxrpc_rack_detect_loss_and_arm_timer(call, &summary); 1192 rxrpc_tlp_process_ack(call, &summary); 1193 if (call->tlp_serial && after_eq(summary.acked_serial, call->tlp_serial)) 1194 call->tlp_serial = 0; 1195 1196 send_response: 1197 if (summary.ack_reason == RXRPC_ACK_PING) 1198 rxrpc_send_ACK(call, RXRPC_ACK_PING_RESPONSE, summary.ack_serial, 1199 rxrpc_propose_ack_respond_to_ping); 1200 else if (sp->hdr.flags & RXRPC_REQUEST_ACK) 1201 rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, summary.ack_serial, 1202 rxrpc_propose_ack_respond_to_ack); 1203 } 1204 1205 /* 1206 * Process an ACKALL packet. 1207 */ 1208 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 1209 { 1210 struct rxrpc_ack_summary summary = { 0 }; 1211 1212 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 1213 rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ackall); 1214 } 1215 1216 /* 1217 * Process an ABORT packet directed at a call. 1218 */ 1219 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 1220 { 1221 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1222 1223 trace_rxrpc_rx_abort(call, sp->hdr.serial, skb->priority); 1224 1225 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1226 skb->priority, -ECONNABORTED); 1227 } 1228 1229 /* 1230 * Process an incoming call packet. 1231 */ 1232 void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb) 1233 { 1234 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1235 unsigned long timo; 1236 1237 _enter("%p,%p", call, skb); 1238 1239 if (sp->hdr.serviceId != call->dest_srx.srx_service) 1240 call->dest_srx.srx_service = sp->hdr.serviceId; 1241 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1242 call->rx_serial = sp->hdr.serial; 1243 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1244 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1245 1246 timo = READ_ONCE(call->next_rx_timo); 1247 if (timo) { 1248 ktime_t delay = ms_to_ktime(timo); 1249 1250 call->expect_rx_by = ktime_add(ktime_get_real(), delay); 1251 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_expect_rx); 1252 } 1253 1254 switch (sp->hdr.type) { 1255 case RXRPC_PACKET_TYPE_DATA: 1256 return rxrpc_input_data(call, skb); 1257 1258 case RXRPC_PACKET_TYPE_ACK: 1259 return rxrpc_input_ack(call, skb); 1260 1261 case RXRPC_PACKET_TYPE_BUSY: 1262 /* Just ignore BUSY packets from the server; the retry and 1263 * lifespan timers will take care of business. BUSY packets 1264 * from the client don't make sense. 1265 */ 1266 return; 1267 1268 case RXRPC_PACKET_TYPE_ABORT: 1269 return rxrpc_input_abort(call, skb); 1270 1271 case RXRPC_PACKET_TYPE_ACKALL: 1272 return rxrpc_input_ackall(call, skb); 1273 1274 default: 1275 break; 1276 } 1277 } 1278 1279 /* 1280 * Handle a new service call on a channel implicitly completing the preceding 1281 * call on that channel. This does not apply to client conns. 1282 * 1283 * TODO: If callNumber > call_id + 1, renegotiate security. 1284 */ 1285 void rxrpc_implicit_end_call(struct rxrpc_call *call, struct sk_buff *skb) 1286 { 1287 switch (__rxrpc_call_state(call)) { 1288 case RXRPC_CALL_SERVER_AWAIT_ACK: 1289 rxrpc_call_completed(call); 1290 fallthrough; 1291 case RXRPC_CALL_COMPLETE: 1292 break; 1293 default: 1294 rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ESHUTDOWN, 1295 rxrpc_eproto_improper_term); 1296 trace_rxrpc_improper_term(call); 1297 break; 1298 } 1299 1300 rxrpc_input_call_event(call); 1301 } 1302