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 skb_queue_tail(&call->recvmsg_queue, skb); 452 rxrpc_input_update_ack_window(call, window, wtop); 453 trace_rxrpc_receive(call, last ? why + 1 : why, sp->hdr.serial, sp->hdr.seq); 454 if (last) 455 rxrpc_end_rx_phase(call, sp->hdr.serial); 456 } 457 458 /* 459 * Process a DATA packet. 460 */ 461 static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb, 462 bool *_notify, rxrpc_serial_t *_ack_serial, int *_ack_reason) 463 { 464 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 465 struct sk_buff *oos; 466 rxrpc_serial_t serial = sp->hdr.serial; 467 unsigned int sack = call->ackr_sack_base; 468 rxrpc_seq_t window = call->ackr_window; 469 rxrpc_seq_t wtop = call->ackr_wtop; 470 rxrpc_seq_t wlimit = window + call->rx_winsize - 1; 471 rxrpc_seq_t seq = sp->hdr.seq; 472 bool last = sp->hdr.flags & RXRPC_LAST_PACKET; 473 int ack_reason = -1; 474 475 rxrpc_inc_stat(call->rxnet, stat_rx_data); 476 if (sp->hdr.flags & RXRPC_REQUEST_ACK) 477 rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack); 478 if (sp->hdr.flags & RXRPC_JUMBO_PACKET) 479 rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo); 480 481 if (last) { 482 if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) && 483 seq + 1 != wtop) 484 return rxrpc_proto_abort(call, seq, rxrpc_eproto_different_last); 485 } else { 486 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 487 after_eq(seq, wtop)) { 488 pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n", 489 call->debug_id, seq, window, wtop, wlimit); 490 return rxrpc_proto_abort(call, seq, rxrpc_eproto_data_after_last); 491 } 492 } 493 494 if (after(seq, call->rx_highest_seq)) 495 call->rx_highest_seq = seq; 496 497 trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags); 498 499 if (before(seq, window)) { 500 ack_reason = RXRPC_ACK_DUPLICATE; 501 goto send_ack; 502 } 503 if (after(seq, wlimit)) { 504 ack_reason = RXRPC_ACK_EXCEEDS_WINDOW; 505 goto send_ack; 506 } 507 508 /* Queue the packet. */ 509 if (seq == window) { 510 if (sp->hdr.flags & RXRPC_REQUEST_ACK) 511 ack_reason = RXRPC_ACK_REQUESTED; 512 /* Send an immediate ACK if we fill in a hole */ 513 else if (!skb_queue_empty(&call->rx_oos_queue)) 514 ack_reason = RXRPC_ACK_DELAY; 515 516 window++; 517 if (after(window, wtop)) { 518 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_none); 519 wtop = window; 520 } else { 521 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_advance); 522 sack = (sack + 1) % RXRPC_SACK_SIZE; 523 } 524 525 526 rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg); 527 528 rxrpc_input_queue_data(call, skb, window, wtop, rxrpc_receive_queue); 529 *_notify = true; 530 531 while ((oos = skb_peek(&call->rx_oos_queue))) { 532 struct rxrpc_skb_priv *osp = rxrpc_skb(oos); 533 534 if (after(osp->hdr.seq, window)) 535 break; 536 537 __skb_unlink(oos, &call->rx_oos_queue); 538 last = osp->hdr.flags & RXRPC_LAST_PACKET; 539 seq = osp->hdr.seq; 540 call->ackr_sack_table[sack] = 0; 541 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_fill); 542 sack = (sack + 1) % RXRPC_SACK_SIZE; 543 544 window++; 545 rxrpc_input_queue_data(call, oos, window, wtop, 546 rxrpc_receive_queue_oos); 547 } 548 549 call->ackr_sack_base = sack; 550 } else { 551 unsigned int slot; 552 553 ack_reason = RXRPC_ACK_OUT_OF_SEQUENCE; 554 555 slot = seq - window; 556 sack = (sack + slot) % RXRPC_SACK_SIZE; 557 558 if (call->ackr_sack_table[sack % RXRPC_SACK_SIZE]) { 559 ack_reason = RXRPC_ACK_DUPLICATE; 560 goto send_ack; 561 } 562 563 call->ackr_sack_table[sack % RXRPC_SACK_SIZE] |= 1; 564 trace_rxrpc_sack(call, seq, sack, rxrpc_sack_oos); 565 566 if (after(seq + 1, wtop)) { 567 wtop = seq + 1; 568 rxrpc_input_update_ack_window(call, window, wtop); 569 } 570 571 skb_queue_walk(&call->rx_oos_queue, oos) { 572 struct rxrpc_skb_priv *osp = rxrpc_skb(oos); 573 574 if (after(osp->hdr.seq, seq)) { 575 rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos); 576 __skb_queue_before(&call->rx_oos_queue, oos, skb); 577 goto oos_queued; 578 } 579 } 580 581 rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos); 582 __skb_queue_tail(&call->rx_oos_queue, skb); 583 oos_queued: 584 trace_rxrpc_receive(call, last ? rxrpc_receive_oos_last : rxrpc_receive_oos, 585 sp->hdr.serial, sp->hdr.seq); 586 } 587 588 send_ack: 589 if (ack_reason >= 0) { 590 if (rxrpc_ack_priority[ack_reason] > rxrpc_ack_priority[*_ack_reason]) { 591 *_ack_serial = serial; 592 *_ack_reason = ack_reason; 593 } else if (rxrpc_ack_priority[ack_reason] == rxrpc_ack_priority[*_ack_reason] && 594 ack_reason == RXRPC_ACK_REQUESTED) { 595 *_ack_serial = serial; 596 *_ack_reason = ack_reason; 597 } 598 } 599 } 600 601 /* 602 * Split a jumbo packet and file the bits separately. 603 */ 604 static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb) 605 { 606 struct rxrpc_jumbo_header jhdr; 607 struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp; 608 struct sk_buff *jskb; 609 rxrpc_serial_t ack_serial = 0; 610 unsigned int offset = sizeof(struct rxrpc_wire_header); 611 unsigned int len = skb->len - offset; 612 bool notify = false; 613 int ack_reason = 0, count = 1, stat_ix; 614 615 while (sp->hdr.flags & RXRPC_JUMBO_PACKET) { 616 if (len < RXRPC_JUMBO_SUBPKTLEN) 617 goto protocol_error; 618 if (sp->hdr.flags & RXRPC_LAST_PACKET) 619 goto protocol_error; 620 if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN, 621 &jhdr, sizeof(jhdr)) < 0) 622 goto protocol_error; 623 624 jskb = skb_clone(skb, GFP_NOFS); 625 if (!jskb) { 626 kdebug("couldn't clone"); 627 return false; 628 } 629 rxrpc_new_skb(jskb, rxrpc_skb_new_jumbo_subpacket); 630 jsp = rxrpc_skb(jskb); 631 jsp->offset = offset; 632 jsp->len = RXRPC_JUMBO_DATALEN; 633 rxrpc_input_data_one(call, jskb, ¬ify, &ack_serial, &ack_reason); 634 rxrpc_free_skb(jskb, rxrpc_skb_put_jumbo_subpacket); 635 636 sp->hdr.flags = jhdr.flags; 637 sp->hdr._rsvd = ntohs(jhdr._rsvd); 638 sp->hdr.seq++; 639 sp->hdr.serial++; 640 offset += RXRPC_JUMBO_SUBPKTLEN; 641 len -= RXRPC_JUMBO_SUBPKTLEN; 642 count++; 643 } 644 645 sp->offset = offset; 646 sp->len = len; 647 rxrpc_input_data_one(call, skb, ¬ify, &ack_serial, &ack_reason); 648 649 stat_ix = umin(count, ARRAY_SIZE(call->rxnet->stat_rx_jumbo)) - 1; 650 atomic_inc(&call->rxnet->stat_rx_jumbo[stat_ix]); 651 652 if (ack_reason > 0) { 653 rxrpc_send_ACK(call, ack_reason, ack_serial, 654 rxrpc_propose_ack_input_data); 655 } else { 656 call->ackr_nr_unacked++; 657 rxrpc_propose_delay_ACK(call, sp->hdr.serial, 658 rxrpc_propose_ack_input_data); 659 } 660 if (notify) { 661 trace_rxrpc_notify_socket(call->debug_id, sp->hdr.serial); 662 rxrpc_notify_socket(call); 663 } 664 return true; 665 666 protocol_error: 667 return false; 668 } 669 670 /* 671 * Process a DATA packet, adding the packet to the Rx ring. The caller's 672 * packet ref must be passed on or discarded. 673 */ 674 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb) 675 { 676 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 677 rxrpc_serial_t serial = sp->hdr.serial; 678 rxrpc_seq_t seq0 = sp->hdr.seq; 679 680 _enter("{%x,%x,%x},{%u,%x}", 681 call->ackr_window, call->ackr_wtop, call->rx_highest_seq, 682 skb->len, seq0); 683 684 if (__rxrpc_call_is_complete(call)) 685 return; 686 687 switch (__rxrpc_call_state(call)) { 688 case RXRPC_CALL_CLIENT_SEND_REQUEST: 689 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 690 /* Received data implicitly ACKs all of the request 691 * packets we sent when we're acting as a client. 692 */ 693 if (!rxrpc_receiving_reply(call)) 694 goto out_notify; 695 break; 696 697 case RXRPC_CALL_SERVER_RECV_REQUEST: { 698 unsigned long timo = READ_ONCE(call->next_req_timo); 699 700 if (timo) { 701 ktime_t delay = ms_to_ktime(timo); 702 703 call->expect_req_by = ktime_add(ktime_get_real(), delay); 704 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_idle); 705 } 706 break; 707 } 708 709 default: 710 break; 711 } 712 713 if (!rxrpc_input_split_jumbo(call, skb)) { 714 rxrpc_proto_abort(call, sp->hdr.seq, rxrpc_badmsg_bad_jumbo); 715 goto out_notify; 716 } 717 return; 718 719 out_notify: 720 trace_rxrpc_notify_socket(call->debug_id, serial); 721 rxrpc_notify_socket(call); 722 _leave(" [queued]"); 723 } 724 725 /* 726 * See if there's a cached RTT probe to complete. 727 */ 728 static void rxrpc_complete_rtt_probe(struct rxrpc_call *call, 729 ktime_t resp_time, 730 rxrpc_serial_t acked_serial, 731 rxrpc_serial_t ack_serial, 732 enum rxrpc_rtt_rx_trace type) 733 { 734 rxrpc_serial_t orig_serial; 735 unsigned long avail; 736 ktime_t sent_at; 737 bool matched = false; 738 int i; 739 740 avail = READ_ONCE(call->rtt_avail); 741 smp_rmb(); /* Read avail bits before accessing data. */ 742 743 for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) { 744 if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail)) 745 continue; 746 747 sent_at = call->rtt_sent_at[i]; 748 orig_serial = call->rtt_serial[i]; 749 750 if (orig_serial == acked_serial) { 751 clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 752 smp_mb(); /* Read data before setting avail bit */ 753 set_bit(i, &call->rtt_avail); 754 rxrpc_call_add_rtt(call, type, i, acked_serial, ack_serial, 755 sent_at, resp_time); 756 matched = true; 757 } 758 759 /* If a later serial is being acked, then mark this slot as 760 * being available. 761 */ 762 if (after(acked_serial, orig_serial)) { 763 trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i, 764 orig_serial, acked_serial, 0, 0, 0); 765 clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 766 smp_wmb(); 767 set_bit(i, &call->rtt_avail); 768 } 769 } 770 771 if (!matched) 772 trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0, 0); 773 } 774 775 /* 776 * Process the extra information that may be appended to an ACK packet 777 */ 778 static void rxrpc_input_ack_trailer(struct rxrpc_call *call, struct sk_buff *skb, 779 struct rxrpc_acktrailer *trailer) 780 { 781 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 782 struct rxrpc_peer *peer = call->peer; 783 unsigned int max_data, capacity; 784 bool wake = false; 785 u32 max_mtu = ntohl(trailer->maxMTU); 786 //u32 if_mtu = ntohl(trailer->ifMTU); 787 u32 rwind = ntohl(trailer->rwind); 788 u32 jumbo_max = ntohl(trailer->jumbo_max); 789 790 if (rwind > RXRPC_TX_MAX_WINDOW) 791 rwind = RXRPC_TX_MAX_WINDOW; 792 if (call->tx_winsize != rwind) { 793 if (rwind > call->tx_winsize) 794 wake = true; 795 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake); 796 call->tx_winsize = rwind; 797 } 798 799 max_mtu = clamp(max_mtu, 500, 65535); 800 peer->ackr_max_data = max_mtu; 801 802 if (max_mtu < peer->max_data) { 803 trace_rxrpc_pmtud_reduce(peer, sp->hdr.serial, max_mtu, 804 rxrpc_pmtud_reduce_ack); 805 write_seqcount_begin(&peer->mtu_lock); 806 peer->max_data = max_mtu; 807 write_seqcount_end(&peer->mtu_lock); 808 } 809 810 max_data = umin(max_mtu, peer->max_data); 811 capacity = max_data; 812 capacity += sizeof(struct rxrpc_jumbo_header); /* First subpacket has main hdr, not jumbo */ 813 capacity /= sizeof(struct rxrpc_jumbo_header) + RXRPC_JUMBO_DATALEN; 814 815 if (jumbo_max == 0) { 816 /* The peer says it supports pmtu discovery */ 817 peer->ackr_adv_pmtud = true; 818 } else { 819 peer->ackr_adv_pmtud = false; 820 capacity = clamp(capacity, 1, jumbo_max); 821 } 822 823 call->tx_jumbo_max = capacity; 824 825 if (wake) 826 wake_up(&call->waitq); 827 } 828 829 #if defined(CONFIG_X86) && __GNUC__ && !defined(__clang__) 830 /* Clang doesn't support the %z constraint modifier */ 831 #define shiftr_adv_rotr(shift_from, rotate_into) ({ \ 832 asm(" shr%z1 %1\n" \ 833 " inc %0\n" \ 834 " rcr%z2 %2\n" \ 835 : "+d"(shift_from), "+m"(*(shift_from)), "+rm"(rotate_into) \ 836 ); \ 837 }) 838 #else 839 #define shiftr_adv_rotr(shift_from, rotate_into) ({ \ 840 typeof(rotate_into) __bit0 = *(shift_from) & 1; \ 841 *(shift_from) >>= 1; \ 842 shift_from++; \ 843 rotate_into >>= 1; \ 844 rotate_into |= __bit0 << (sizeof(rotate_into) * 8 - 1); \ 845 }) 846 #endif 847 848 /* 849 * Deal with RTT samples from soft ACKs. 850 */ 851 static void rxrpc_input_soft_rtt(struct rxrpc_call *call, 852 struct rxrpc_ack_summary *summary, 853 struct rxrpc_txqueue *tq) 854 { 855 for (int ix = 0; ix < RXRPC_NR_TXQUEUE; ix++) 856 if (summary->acked_serial == tq->segment_serial[ix]) 857 return rxrpc_add_data_rtt_sample(call, summary, tq, ix); 858 } 859 860 /* 861 * Process a batch of soft ACKs specific to a transmission queue segment. 862 */ 863 static void rxrpc_input_soft_ack_tq(struct rxrpc_call *call, 864 struct rxrpc_ack_summary *summary, 865 struct rxrpc_txqueue *tq, 866 unsigned long extracted_acks, 867 int nr_reported, 868 rxrpc_seq_t seq, 869 rxrpc_seq_t *lowest_nak) 870 { 871 unsigned long old_reported = 0, flipped, new_acks = 0; 872 unsigned long a_to_n, n_to_a = 0; 873 int new, a, n; 874 875 if (tq->nr_reported_acks > 0) 876 old_reported = ~0UL >> (RXRPC_NR_TXQUEUE - tq->nr_reported_acks); 877 878 _enter("{%x,%lx,%d},%lx,%d,%x", 879 tq->qbase, tq->segment_acked, tq->nr_reported_acks, 880 extracted_acks, nr_reported, seq); 881 882 _debug("[%x]", tq->qbase); 883 _debug("tq %16lx %u", tq->segment_acked, tq->nr_reported_acks); 884 _debug("sack %16lx %u", extracted_acks, nr_reported); 885 886 /* See how many previously logged ACKs/NAKs have flipped. */ 887 flipped = (tq->segment_acked ^ extracted_acks) & old_reported; 888 if (flipped) { 889 n_to_a = ~tq->segment_acked & flipped; /* Old NAK -> ACK */ 890 a_to_n = tq->segment_acked & flipped; /* Old ACK -> NAK */ 891 a = hweight_long(n_to_a); 892 n = hweight_long(a_to_n); 893 _debug("flip %16lx", flipped); 894 _debug("ntoa %16lx %d", n_to_a, a); 895 _debug("aton %16lx %d", a_to_n, n); 896 call->acks_nr_sacks += a - n; 897 call->acks_nr_snacks += n - a; 898 summary->nr_new_sacks += a; 899 summary->nr_new_snacks += n; 900 } 901 902 /* See how many new ACKs/NAKs have been acquired. */ 903 new = nr_reported - tq->nr_reported_acks; 904 if (new > 0) { 905 new_acks = extracted_acks & ~old_reported; 906 if (new_acks) { 907 a = hweight_long(new_acks); 908 n = new - a; 909 _debug("new_a %16lx new=%d a=%d n=%d", new_acks, new, a, n); 910 call->acks_nr_sacks += a; 911 call->acks_nr_snacks += n; 912 summary->nr_new_sacks += a; 913 summary->nr_new_snacks += n; 914 } else { 915 call->acks_nr_snacks += new; 916 summary->nr_new_snacks += new; 917 } 918 } 919 920 tq->nr_reported_acks = nr_reported; 921 tq->segment_acked = extracted_acks; 922 trace_rxrpc_apply_acks(call, tq); 923 924 if (extracted_acks != ~0UL) { 925 rxrpc_seq_t lowest = seq + ffz(extracted_acks); 926 927 if (before(lowest, *lowest_nak)) 928 *lowest_nak = lowest; 929 } 930 931 if (summary->acked_serial) 932 rxrpc_input_soft_rtt(call, summary, tq); 933 934 new_acks |= n_to_a; 935 if (new_acks) 936 rxrpc_input_rack(call, summary, tq, new_acks); 937 938 if (call->tlp_serial && 939 rxrpc_seq_in_txq(tq, call->tlp_seq) && 940 test_bit(call->tlp_seq - tq->qbase, &new_acks)) 941 summary->tlp_probe_acked = true; 942 } 943 944 /* 945 * Process individual soft ACKs. 946 * 947 * Each ACK in the array corresponds to one packet and can be either an ACK or 948 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 949 * packets that lie beyond the end of the ACK list are scheduled for resend by 950 * the timer on the basis that the peer might just not have processed them at 951 * the time the ACK was sent. 952 */ 953 static void rxrpc_input_soft_acks(struct rxrpc_call *call, 954 struct rxrpc_ack_summary *summary, 955 struct sk_buff *skb) 956 { 957 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 958 struct rxrpc_txqueue *tq = call->tx_queue; 959 unsigned long extracted = ~0UL; 960 unsigned int nr = 0; 961 rxrpc_seq_t seq = call->acks_hard_ack + 1; 962 rxrpc_seq_t lowest_nak = seq + sp->ack.nr_acks; 963 u8 *acks = skb->data + sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket); 964 965 _enter("%x,%x,%u", tq->qbase, seq, sp->ack.nr_acks); 966 967 while (after(seq, tq->qbase + RXRPC_NR_TXQUEUE - 1)) 968 tq = tq->next; 969 970 for (unsigned int i = 0; i < sp->ack.nr_acks; i++) { 971 /* Decant ACKs until we hit a txqueue boundary. */ 972 shiftr_adv_rotr(acks, extracted); 973 if (i == 256) { 974 acks -= i; 975 i = 0; 976 } 977 seq++; 978 nr++; 979 if ((seq & RXRPC_TXQ_MASK) != 0) 980 continue; 981 982 _debug("bound %16lx %u", extracted, nr); 983 984 rxrpc_input_soft_ack_tq(call, summary, tq, extracted, RXRPC_NR_TXQUEUE, 985 seq - RXRPC_NR_TXQUEUE, &lowest_nak); 986 extracted = ~0UL; 987 nr = 0; 988 tq = tq->next; 989 prefetch(tq); 990 } 991 992 if (nr) { 993 unsigned int nr_reported = seq & RXRPC_TXQ_MASK; 994 995 extracted >>= RXRPC_NR_TXQUEUE - nr_reported; 996 _debug("tail %16lx %u", extracted, nr_reported); 997 rxrpc_input_soft_ack_tq(call, summary, tq, extracted, nr_reported, 998 seq & ~RXRPC_TXQ_MASK, &lowest_nak); 999 } 1000 1001 /* We *can* have more nacks than we did - the peer is permitted to drop 1002 * packets it has soft-acked and re-request them. Further, it is 1003 * possible for the nack distribution to change whilst the number of 1004 * nacks stays the same or goes down. 1005 */ 1006 if (lowest_nak != call->acks_lowest_nak) { 1007 call->acks_lowest_nak = lowest_nak; 1008 summary->new_low_snack = true; 1009 } 1010 1011 _debug("summary A=%d+%d N=%d+%d", 1012 call->acks_nr_sacks, summary->nr_new_sacks, 1013 call->acks_nr_snacks, summary->nr_new_snacks); 1014 } 1015 1016 /* 1017 * Return true if the ACK is valid - ie. it doesn't appear to have regressed 1018 * with respect to the ack state conveyed by preceding ACKs. 1019 */ 1020 static bool rxrpc_is_ack_valid(struct rxrpc_call *call, 1021 rxrpc_seq_t hard_ack, rxrpc_seq_t prev_pkt) 1022 { 1023 rxrpc_seq_t base = READ_ONCE(call->acks_hard_ack); 1024 1025 if (after(hard_ack, base)) 1026 return true; /* The window advanced */ 1027 1028 if (before(hard_ack, base)) 1029 return false; /* firstPacket regressed */ 1030 1031 if (after_eq(prev_pkt, call->acks_prev_seq)) 1032 return true; /* previousPacket hasn't regressed. */ 1033 1034 /* Some rx implementations put a serial number in previousPacket. */ 1035 if (after(prev_pkt, base + call->tx_winsize)) 1036 return false; 1037 return true; 1038 } 1039 1040 /* 1041 * Process an ACK packet. 1042 * 1043 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 1044 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 1045 * 1046 * A hard-ACK means that a packet has been processed and may be discarded; a 1047 * soft-ACK means that the packet may be discarded and retransmission 1048 * requested. A phase is complete when all packets are hard-ACK'd. 1049 */ 1050 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb) 1051 { 1052 struct rxrpc_ack_summary summary = { 0 }; 1053 struct rxrpc_acktrailer trailer; 1054 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1055 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 1056 int nr_acks, offset, ioffset; 1057 1058 _enter(""); 1059 1060 offset = sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket); 1061 1062 summary.ack_serial = sp->hdr.serial; 1063 first_soft_ack = sp->ack.first_ack; 1064 prev_pkt = sp->ack.prev_ack; 1065 nr_acks = sp->ack.nr_acks; 1066 hard_ack = first_soft_ack - 1; 1067 summary.acked_serial = sp->ack.acked_serial; 1068 summary.ack_reason = (sp->ack.reason < RXRPC_ACK__INVALID ? 1069 sp->ack.reason : RXRPC_ACK__INVALID); 1070 1071 trace_rxrpc_rx_ack(call, sp); 1072 rxrpc_inc_stat(call->rxnet, stat_rx_acks[summary.ack_reason]); 1073 prefetch(call->tx_queue); 1074 1075 /* If we get an EXCEEDS_WINDOW ACK from the server, it probably 1076 * indicates that the client address changed due to NAT. The server 1077 * lost the call because it switched to a different peer. 1078 */ 1079 if (unlikely(summary.ack_reason == RXRPC_ACK_EXCEEDS_WINDOW) && 1080 hard_ack == 0 && 1081 prev_pkt == 0 && 1082 rxrpc_is_client_call(call)) { 1083 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1084 0, -ENETRESET); 1085 goto send_response; 1086 } 1087 1088 /* If we get an OUT_OF_SEQUENCE ACK from the server, that can also 1089 * indicate a change of address. However, we can retransmit the call 1090 * if we still have it buffered to the beginning. 1091 */ 1092 if (unlikely(summary.ack_reason == RXRPC_ACK_OUT_OF_SEQUENCE) && 1093 hard_ack == 0 && 1094 prev_pkt == 0 && 1095 call->tx_bottom == 0 && 1096 rxrpc_is_client_call(call)) { 1097 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1098 0, -ENETRESET); 1099 goto send_response; 1100 } 1101 1102 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 1103 if (!rxrpc_is_ack_valid(call, hard_ack, prev_pkt)) { 1104 trace_rxrpc_rx_discard_ack(call, summary.ack_serial, hard_ack, prev_pkt); 1105 goto send_response; /* Still respond if requested. */ 1106 } 1107 1108 trailer.maxMTU = 0; 1109 ioffset = offset + nr_acks + 3; 1110 if (skb->len >= ioffset + sizeof(trailer) && 1111 skb_copy_bits(skb, ioffset, &trailer, sizeof(trailer)) < 0) 1112 return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack_trailer); 1113 1114 if (nr_acks > 0) 1115 skb_condense(skb); 1116 1117 call->acks_latest_ts = ktime_get_real(); 1118 call->acks_hard_ack = hard_ack; 1119 call->acks_prev_seq = prev_pkt; 1120 1121 if (summary.acked_serial) { 1122 switch (summary.ack_reason) { 1123 case RXRPC_ACK_PING_RESPONSE: 1124 rxrpc_complete_rtt_probe(call, call->acks_latest_ts, 1125 summary.acked_serial, summary.ack_serial, 1126 rxrpc_rtt_rx_ping_response); 1127 break; 1128 default: 1129 if (after(summary.acked_serial, call->acks_highest_serial)) 1130 call->acks_highest_serial = summary.acked_serial; 1131 summary.rtt_sample_avail = true; 1132 break; 1133 } 1134 } 1135 1136 /* Parse rwind and mtu sizes if provided. */ 1137 if (trailer.maxMTU) 1138 rxrpc_input_ack_trailer(call, skb, &trailer); 1139 1140 if (hard_ack + 1 == 0) 1141 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_zero); 1142 1143 /* Ignore ACKs unless we are or have just been transmitting. */ 1144 switch (__rxrpc_call_state(call)) { 1145 case RXRPC_CALL_CLIENT_SEND_REQUEST: 1146 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 1147 case RXRPC_CALL_SERVER_SEND_REPLY: 1148 case RXRPC_CALL_SERVER_AWAIT_ACK: 1149 break; 1150 default: 1151 goto send_response; 1152 } 1153 1154 if (before(hard_ack, call->tx_bottom) || 1155 after(hard_ack, call->tx_top)) 1156 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_outside_window); 1157 if (nr_acks > call->tx_top - hard_ack) 1158 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_sack_overflow); 1159 1160 if (after(hard_ack, call->tx_bottom)) { 1161 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 1162 rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ack); 1163 goto send_response; 1164 } 1165 } 1166 1167 if (nr_acks > 0) { 1168 if (offset > (int)skb->len - nr_acks) 1169 return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_short_sack); 1170 rxrpc_input_soft_acks(call, &summary, skb); 1171 } 1172 1173 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) && 1174 call->acks_nr_sacks == call->tx_top - hard_ack && 1175 rxrpc_is_client_call(call)) 1176 rxrpc_propose_ping(call, summary.ack_serial, 1177 rxrpc_propose_ack_ping_for_lost_reply); 1178 1179 /* Drive the congestion management algorithm first and then RACK-TLP as 1180 * the latter depends on the state/change in state in the former. 1181 */ 1182 rxrpc_congestion_management(call, &summary); 1183 rxrpc_rack_detect_loss_and_arm_timer(call, &summary); 1184 rxrpc_tlp_process_ack(call, &summary); 1185 if (call->tlp_serial && after_eq(summary.acked_serial, call->tlp_serial)) 1186 call->tlp_serial = 0; 1187 1188 send_response: 1189 if (summary.ack_reason == RXRPC_ACK_PING) 1190 rxrpc_send_ACK(call, RXRPC_ACK_PING_RESPONSE, summary.ack_serial, 1191 rxrpc_propose_ack_respond_to_ping); 1192 else if (sp->hdr.flags & RXRPC_REQUEST_ACK) 1193 rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, summary.ack_serial, 1194 rxrpc_propose_ack_respond_to_ack); 1195 } 1196 1197 /* 1198 * Process an ACKALL packet. 1199 */ 1200 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 1201 { 1202 struct rxrpc_ack_summary summary = { 0 }; 1203 1204 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 1205 rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ackall); 1206 } 1207 1208 /* 1209 * Process an ABORT packet directed at a call. 1210 */ 1211 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 1212 { 1213 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1214 1215 trace_rxrpc_rx_abort(call, sp->hdr.serial, skb->priority); 1216 1217 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1218 skb->priority, -ECONNABORTED); 1219 } 1220 1221 /* 1222 * Process an incoming call packet. 1223 */ 1224 void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb) 1225 { 1226 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1227 unsigned long timo; 1228 1229 _enter("%p,%p", call, skb); 1230 1231 if (sp->hdr.serviceId != call->dest_srx.srx_service) 1232 call->dest_srx.srx_service = sp->hdr.serviceId; 1233 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1234 call->rx_serial = sp->hdr.serial; 1235 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1236 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1237 1238 timo = READ_ONCE(call->next_rx_timo); 1239 if (timo) { 1240 ktime_t delay = ms_to_ktime(timo); 1241 1242 call->expect_rx_by = ktime_add(ktime_get_real(), delay); 1243 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_expect_rx); 1244 } 1245 1246 switch (sp->hdr.type) { 1247 case RXRPC_PACKET_TYPE_DATA: 1248 return rxrpc_input_data(call, skb); 1249 1250 case RXRPC_PACKET_TYPE_ACK: 1251 return rxrpc_input_ack(call, skb); 1252 1253 case RXRPC_PACKET_TYPE_BUSY: 1254 /* Just ignore BUSY packets from the server; the retry and 1255 * lifespan timers will take care of business. BUSY packets 1256 * from the client don't make sense. 1257 */ 1258 return; 1259 1260 case RXRPC_PACKET_TYPE_ABORT: 1261 return rxrpc_input_abort(call, skb); 1262 1263 case RXRPC_PACKET_TYPE_ACKALL: 1264 return rxrpc_input_ackall(call, skb); 1265 1266 default: 1267 break; 1268 } 1269 } 1270 1271 /* 1272 * Handle a new service call on a channel implicitly completing the preceding 1273 * call on that channel. This does not apply to client conns. 1274 * 1275 * TODO: If callNumber > call_id + 1, renegotiate security. 1276 */ 1277 void rxrpc_implicit_end_call(struct rxrpc_call *call, struct sk_buff *skb) 1278 { 1279 switch (__rxrpc_call_state(call)) { 1280 case RXRPC_CALL_SERVER_AWAIT_ACK: 1281 rxrpc_call_completed(call); 1282 fallthrough; 1283 case RXRPC_CALL_COMPLETE: 1284 break; 1285 default: 1286 rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ESHUTDOWN, 1287 rxrpc_eproto_improper_term); 1288 trace_rxrpc_improper_term(call); 1289 break; 1290 } 1291 1292 rxrpc_input_call_event(call); 1293 } 1294