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![David Howells](/assets/img/avatar_default.png)
Fix three cases of overproduction of wakeups: (1) rxrpc_input_split_jumbo() conditionally notifies the app that there's data for recvmsg() to collect if it queues some data - and then its only caller, rxrpc_input_data(), goes and wakes up recvmsg() anyway. Fix the rxrpc_input_data() to only do the wakeup in failure cases. (2) If a DATA packet is received for a call by the I/O thread whilst recvmsg() is busy draining the call's rx queue in the app thread, the call will left on the recvmsg() queue for recvmsg() to pick up, even though there isn't any data on it. This can cause an unexpected recvmsg() with a 0 return and no MSG_EOR set after the reply has been posted to a service call. Fix this by discarding pending calls from the recvmsg() queue that don't need servicing yet. (3) Not-yet-completed calls get requeued after having data read from them, even if they have no data to read. Fix this by only requeuing them if they have data waiting on them; if they don't, the I/O thread will requeue them when data arrives or they fail. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/3386149.1676497685@warthog.procyon.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
1030 lines
28 KiB
C
1030 lines
28 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* Processing of received RxRPC packets
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*
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* Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include "ar-internal.h"
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static void rxrpc_proto_abort(struct rxrpc_call *call, rxrpc_seq_t seq,
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enum rxrpc_abort_reason why)
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{
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rxrpc_abort_call(call, seq, RX_PROTOCOL_ERROR, -EBADMSG, why);
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}
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/*
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* Do TCP-style congestion management [RFC 5681].
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*/
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static void rxrpc_congestion_management(struct rxrpc_call *call,
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struct sk_buff *skb,
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struct rxrpc_ack_summary *summary,
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rxrpc_serial_t acked_serial)
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{
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enum rxrpc_congest_change change = rxrpc_cong_no_change;
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unsigned int cumulative_acks = call->cong_cumul_acks;
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unsigned int cwnd = call->cong_cwnd;
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bool resend = false;
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summary->flight_size =
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(call->tx_top - call->acks_hard_ack) - summary->nr_acks;
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if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
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summary->retrans_timeo = true;
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call->cong_ssthresh = max_t(unsigned int,
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summary->flight_size / 2, 2);
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cwnd = 1;
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if (cwnd >= call->cong_ssthresh &&
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call->cong_mode == RXRPC_CALL_SLOW_START) {
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call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
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call->cong_tstamp = skb->tstamp;
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cumulative_acks = 0;
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}
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}
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cumulative_acks += summary->nr_new_acks;
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cumulative_acks += summary->nr_rot_new_acks;
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if (cumulative_acks > 255)
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cumulative_acks = 255;
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summary->mode = call->cong_mode;
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summary->cwnd = call->cong_cwnd;
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summary->ssthresh = call->cong_ssthresh;
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summary->cumulative_acks = cumulative_acks;
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summary->dup_acks = call->cong_dup_acks;
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switch (call->cong_mode) {
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case RXRPC_CALL_SLOW_START:
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if (summary->saw_nacks)
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goto packet_loss_detected;
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if (summary->cumulative_acks > 0)
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cwnd += 1;
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if (cwnd >= call->cong_ssthresh) {
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call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
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call->cong_tstamp = skb->tstamp;
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}
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goto out;
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case RXRPC_CALL_CONGEST_AVOIDANCE:
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if (summary->saw_nacks)
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goto packet_loss_detected;
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/* We analyse the number of packets that get ACK'd per RTT
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* period and increase the window if we managed to fill it.
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*/
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if (call->peer->rtt_count == 0)
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goto out;
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if (ktime_before(skb->tstamp,
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ktime_add_us(call->cong_tstamp,
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call->peer->srtt_us >> 3)))
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goto out_no_clear_ca;
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change = rxrpc_cong_rtt_window_end;
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call->cong_tstamp = skb->tstamp;
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if (cumulative_acks >= cwnd)
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cwnd++;
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goto out;
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case RXRPC_CALL_PACKET_LOSS:
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if (!summary->saw_nacks)
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goto resume_normality;
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if (summary->new_low_nack) {
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change = rxrpc_cong_new_low_nack;
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call->cong_dup_acks = 1;
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if (call->cong_extra > 1)
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call->cong_extra = 1;
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goto send_extra_data;
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}
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call->cong_dup_acks++;
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if (call->cong_dup_acks < 3)
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goto send_extra_data;
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change = rxrpc_cong_begin_retransmission;
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call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
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call->cong_ssthresh = max_t(unsigned int,
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summary->flight_size / 2, 2);
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cwnd = call->cong_ssthresh + 3;
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call->cong_extra = 0;
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call->cong_dup_acks = 0;
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resend = true;
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goto out;
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case RXRPC_CALL_FAST_RETRANSMIT:
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if (!summary->new_low_nack) {
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if (summary->nr_new_acks == 0)
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cwnd += 1;
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call->cong_dup_acks++;
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if (call->cong_dup_acks == 2) {
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change = rxrpc_cong_retransmit_again;
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call->cong_dup_acks = 0;
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resend = true;
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}
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} else {
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change = rxrpc_cong_progress;
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cwnd = call->cong_ssthresh;
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if (!summary->saw_nacks)
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goto resume_normality;
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}
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goto out;
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default:
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BUG();
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goto out;
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}
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resume_normality:
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change = rxrpc_cong_cleared_nacks;
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call->cong_dup_acks = 0;
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call->cong_extra = 0;
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call->cong_tstamp = skb->tstamp;
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if (cwnd < call->cong_ssthresh)
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call->cong_mode = RXRPC_CALL_SLOW_START;
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else
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call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
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out:
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cumulative_acks = 0;
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out_no_clear_ca:
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if (cwnd >= RXRPC_TX_MAX_WINDOW)
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cwnd = RXRPC_TX_MAX_WINDOW;
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call->cong_cwnd = cwnd;
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call->cong_cumul_acks = cumulative_acks;
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trace_rxrpc_congest(call, summary, acked_serial, change);
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if (resend)
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rxrpc_resend(call, skb);
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return;
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packet_loss_detected:
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change = rxrpc_cong_saw_nack;
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call->cong_mode = RXRPC_CALL_PACKET_LOSS;
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call->cong_dup_acks = 0;
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goto send_extra_data;
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send_extra_data:
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/* Send some previously unsent DATA if we have some to advance the ACK
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* state.
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*/
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if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ||
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summary->nr_acks != call->tx_top - call->acks_hard_ack) {
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call->cong_extra++;
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wake_up(&call->waitq);
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}
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goto out_no_clear_ca;
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}
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/*
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* Degrade the congestion window if we haven't transmitted a packet for >1RTT.
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*/
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void rxrpc_congestion_degrade(struct rxrpc_call *call)
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{
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ktime_t rtt, now;
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if (call->cong_mode != RXRPC_CALL_SLOW_START &&
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call->cong_mode != RXRPC_CALL_CONGEST_AVOIDANCE)
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return;
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if (__rxrpc_call_state(call) == RXRPC_CALL_CLIENT_AWAIT_REPLY)
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return;
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rtt = ns_to_ktime(call->peer->srtt_us * (1000 / 8));
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now = ktime_get_real();
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if (!ktime_before(ktime_add(call->tx_last_sent, rtt), now))
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return;
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trace_rxrpc_reset_cwnd(call, now);
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rxrpc_inc_stat(call->rxnet, stat_tx_data_cwnd_reset);
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call->tx_last_sent = now;
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call->cong_mode = RXRPC_CALL_SLOW_START;
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call->cong_ssthresh = max_t(unsigned int, call->cong_ssthresh,
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call->cong_cwnd * 3 / 4);
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call->cong_cwnd = max_t(unsigned int, call->cong_cwnd / 2, RXRPC_MIN_CWND);
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}
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/*
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* Apply a hard ACK by advancing the Tx window.
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*/
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static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
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struct rxrpc_ack_summary *summary)
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{
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struct rxrpc_txbuf *txb;
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bool rot_last = false;
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list_for_each_entry_rcu(txb, &call->tx_buffer, call_link, false) {
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if (before_eq(txb->seq, call->acks_hard_ack))
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continue;
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summary->nr_rot_new_acks++;
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if (test_bit(RXRPC_TXBUF_LAST, &txb->flags)) {
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set_bit(RXRPC_CALL_TX_LAST, &call->flags);
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rot_last = true;
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}
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if (txb->seq == to)
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break;
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}
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if (rot_last)
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set_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags);
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_enter("%x,%x,%x,%d", to, call->acks_hard_ack, call->tx_top, rot_last);
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if (call->acks_lowest_nak == call->acks_hard_ack) {
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call->acks_lowest_nak = to;
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} else if (after(to, call->acks_lowest_nak)) {
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summary->new_low_nack = true;
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call->acks_lowest_nak = to;
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}
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smp_store_release(&call->acks_hard_ack, to);
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trace_rxrpc_txqueue(call, (rot_last ?
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rxrpc_txqueue_rotate_last :
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rxrpc_txqueue_rotate));
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wake_up(&call->waitq);
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return rot_last;
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}
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/*
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* End the transmission phase of a call.
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*
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* This occurs when we get an ACKALL packet, the first DATA packet of a reply,
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* or a final ACK packet.
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*/
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static void rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
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enum rxrpc_abort_reason abort_why)
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{
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ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
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switch (__rxrpc_call_state(call)) {
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case RXRPC_CALL_CLIENT_SEND_REQUEST:
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case RXRPC_CALL_CLIENT_AWAIT_REPLY:
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if (reply_begun) {
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rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_RECV_REPLY);
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trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
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break;
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}
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rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_REPLY);
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trace_rxrpc_txqueue(call, rxrpc_txqueue_await_reply);
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break;
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case RXRPC_CALL_SERVER_AWAIT_ACK:
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rxrpc_call_completed(call);
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trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
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break;
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default:
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kdebug("end_tx %s", rxrpc_call_states[__rxrpc_call_state(call)]);
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rxrpc_proto_abort(call, call->tx_top, abort_why);
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break;
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}
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}
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/*
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* Begin the reply reception phase of a call.
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*/
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static bool rxrpc_receiving_reply(struct rxrpc_call *call)
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{
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struct rxrpc_ack_summary summary = { 0 };
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unsigned long now, timo;
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rxrpc_seq_t top = READ_ONCE(call->tx_top);
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if (call->ackr_reason) {
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now = jiffies;
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timo = now + MAX_JIFFY_OFFSET;
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WRITE_ONCE(call->delay_ack_at, timo);
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trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
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}
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if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
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if (!rxrpc_rotate_tx_window(call, top, &summary)) {
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rxrpc_proto_abort(call, top, rxrpc_eproto_early_reply);
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return false;
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}
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}
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rxrpc_end_tx_phase(call, true, rxrpc_eproto_unexpected_reply);
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return true;
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}
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/*
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* End the packet reception phase.
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*/
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static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
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{
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rxrpc_seq_t whigh = READ_ONCE(call->rx_highest_seq);
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_enter("%d,%s", call->debug_id, rxrpc_call_states[__rxrpc_call_state(call)]);
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trace_rxrpc_receive(call, rxrpc_receive_end, 0, whigh);
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switch (__rxrpc_call_state(call)) {
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case RXRPC_CALL_CLIENT_RECV_REPLY:
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rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_terminal_ack);
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rxrpc_call_completed(call);
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break;
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case RXRPC_CALL_SERVER_RECV_REQUEST:
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rxrpc_set_call_state(call, RXRPC_CALL_SERVER_ACK_REQUEST);
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call->expect_req_by = jiffies + MAX_JIFFY_OFFSET;
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rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_processing_op);
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break;
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default:
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break;
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}
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}
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static void rxrpc_input_update_ack_window(struct rxrpc_call *call,
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rxrpc_seq_t window, rxrpc_seq_t wtop)
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{
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call->ackr_window = window;
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call->ackr_wtop = wtop;
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}
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/*
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* Push a DATA packet onto the Rx queue.
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*/
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static void rxrpc_input_queue_data(struct rxrpc_call *call, struct sk_buff *skb,
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rxrpc_seq_t window, rxrpc_seq_t wtop,
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enum rxrpc_receive_trace why)
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{
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struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
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bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
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__skb_queue_tail(&call->recvmsg_queue, skb);
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rxrpc_input_update_ack_window(call, window, wtop);
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trace_rxrpc_receive(call, last ? why + 1 : why, sp->hdr.serial, sp->hdr.seq);
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if (last)
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rxrpc_end_rx_phase(call, sp->hdr.serial);
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}
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/*
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* Process a DATA packet.
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*/
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static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb,
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bool *_notify)
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{
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struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
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struct sk_buff *oos;
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rxrpc_serial_t serial = sp->hdr.serial;
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unsigned int sack = call->ackr_sack_base;
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rxrpc_seq_t window = call->ackr_window;
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rxrpc_seq_t wtop = call->ackr_wtop;
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rxrpc_seq_t wlimit = window + call->rx_winsize - 1;
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rxrpc_seq_t seq = sp->hdr.seq;
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bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
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int ack_reason = -1;
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rxrpc_inc_stat(call->rxnet, stat_rx_data);
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if (sp->hdr.flags & RXRPC_REQUEST_ACK)
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rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
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if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
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rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
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if (last) {
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if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
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seq + 1 != wtop)
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return rxrpc_proto_abort(call, seq, rxrpc_eproto_different_last);
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} else {
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if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
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after_eq(seq, wtop)) {
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pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n",
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call->debug_id, seq, window, wtop, wlimit);
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return rxrpc_proto_abort(call, seq, rxrpc_eproto_data_after_last);
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}
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}
|
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|
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if (after(seq, call->rx_highest_seq))
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call->rx_highest_seq = seq;
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|
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trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags);
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|
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if (before(seq, window)) {
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ack_reason = RXRPC_ACK_DUPLICATE;
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goto send_ack;
|
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}
|
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if (after(seq, wlimit)) {
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ack_reason = RXRPC_ACK_EXCEEDS_WINDOW;
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goto send_ack;
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}
|
|
|
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/* Queue the packet. */
|
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if (seq == window) {
|
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if (sp->hdr.flags & RXRPC_REQUEST_ACK)
|
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ack_reason = RXRPC_ACK_REQUESTED;
|
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/* Send an immediate ACK if we fill in a hole */
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else if (!skb_queue_empty(&call->rx_oos_queue))
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ack_reason = RXRPC_ACK_DELAY;
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else
|
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call->ackr_nr_unacked++;
|
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|
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window++;
|
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if (after(window, wtop)) {
|
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trace_rxrpc_sack(call, seq, sack, rxrpc_sack_none);
|
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wtop = window;
|
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} else {
|
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trace_rxrpc_sack(call, seq, sack, rxrpc_sack_advance);
|
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sack = (sack + 1) % RXRPC_SACK_SIZE;
|
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}
|
|
|
|
|
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rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg);
|
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|
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spin_lock(&call->recvmsg_queue.lock);
|
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rxrpc_input_queue_data(call, skb, window, wtop, rxrpc_receive_queue);
|
|
*_notify = true;
|
|
|
|
while ((oos = skb_peek(&call->rx_oos_queue))) {
|
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struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
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|
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if (after(osp->hdr.seq, window))
|
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break;
|
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|
|
__skb_unlink(oos, &call->rx_oos_queue);
|
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last = osp->hdr.flags & RXRPC_LAST_PACKET;
|
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seq = osp->hdr.seq;
|
|
call->ackr_sack_table[sack] = 0;
|
|
trace_rxrpc_sack(call, seq, sack, rxrpc_sack_fill);
|
|
sack = (sack + 1) % RXRPC_SACK_SIZE;
|
|
|
|
window++;
|
|
rxrpc_input_queue_data(call, oos, window, wtop,
|
|
rxrpc_receive_queue_oos);
|
|
}
|
|
|
|
spin_unlock(&call->recvmsg_queue.lock);
|
|
|
|
call->ackr_sack_base = sack;
|
|
} else {
|
|
unsigned int slot;
|
|
|
|
ack_reason = RXRPC_ACK_OUT_OF_SEQUENCE;
|
|
|
|
slot = seq - window;
|
|
sack = (sack + slot) % RXRPC_SACK_SIZE;
|
|
|
|
if (call->ackr_sack_table[sack % RXRPC_SACK_SIZE]) {
|
|
ack_reason = RXRPC_ACK_DUPLICATE;
|
|
goto send_ack;
|
|
}
|
|
|
|
call->ackr_sack_table[sack % RXRPC_SACK_SIZE] |= 1;
|
|
trace_rxrpc_sack(call, seq, sack, rxrpc_sack_oos);
|
|
|
|
if (after(seq + 1, wtop)) {
|
|
wtop = seq + 1;
|
|
rxrpc_input_update_ack_window(call, window, wtop);
|
|
}
|
|
|
|
skb_queue_walk(&call->rx_oos_queue, oos) {
|
|
struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
|
|
|
|
if (after(osp->hdr.seq, seq)) {
|
|
rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
|
|
__skb_queue_before(&call->rx_oos_queue, oos, skb);
|
|
goto oos_queued;
|
|
}
|
|
}
|
|
|
|
rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
|
|
__skb_queue_tail(&call->rx_oos_queue, skb);
|
|
oos_queued:
|
|
trace_rxrpc_receive(call, last ? rxrpc_receive_oos_last : rxrpc_receive_oos,
|
|
sp->hdr.serial, sp->hdr.seq);
|
|
}
|
|
|
|
send_ack:
|
|
if (ack_reason >= 0)
|
|
rxrpc_send_ACK(call, ack_reason, serial,
|
|
rxrpc_propose_ack_input_data);
|
|
else
|
|
rxrpc_propose_delay_ACK(call, serial,
|
|
rxrpc_propose_ack_input_data);
|
|
}
|
|
|
|
/*
|
|
* Split a jumbo packet and file the bits separately.
|
|
*/
|
|
static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb)
|
|
{
|
|
struct rxrpc_jumbo_header jhdr;
|
|
struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp;
|
|
struct sk_buff *jskb;
|
|
unsigned int offset = sizeof(struct rxrpc_wire_header);
|
|
unsigned int len = skb->len - offset;
|
|
bool notify = false;
|
|
|
|
while (sp->hdr.flags & RXRPC_JUMBO_PACKET) {
|
|
if (len < RXRPC_JUMBO_SUBPKTLEN)
|
|
goto protocol_error;
|
|
if (sp->hdr.flags & RXRPC_LAST_PACKET)
|
|
goto protocol_error;
|
|
if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN,
|
|
&jhdr, sizeof(jhdr)) < 0)
|
|
goto protocol_error;
|
|
|
|
jskb = skb_clone(skb, GFP_NOFS);
|
|
if (!jskb) {
|
|
kdebug("couldn't clone");
|
|
return false;
|
|
}
|
|
rxrpc_new_skb(jskb, rxrpc_skb_new_jumbo_subpacket);
|
|
jsp = rxrpc_skb(jskb);
|
|
jsp->offset = offset;
|
|
jsp->len = RXRPC_JUMBO_DATALEN;
|
|
rxrpc_input_data_one(call, jskb, ¬ify);
|
|
rxrpc_free_skb(jskb, rxrpc_skb_put_jumbo_subpacket);
|
|
|
|
sp->hdr.flags = jhdr.flags;
|
|
sp->hdr._rsvd = ntohs(jhdr._rsvd);
|
|
sp->hdr.seq++;
|
|
sp->hdr.serial++;
|
|
offset += RXRPC_JUMBO_SUBPKTLEN;
|
|
len -= RXRPC_JUMBO_SUBPKTLEN;
|
|
}
|
|
|
|
sp->offset = offset;
|
|
sp->len = len;
|
|
rxrpc_input_data_one(call, skb, ¬ify);
|
|
if (notify) {
|
|
trace_rxrpc_notify_socket(call->debug_id, sp->hdr.serial);
|
|
rxrpc_notify_socket(call);
|
|
}
|
|
return true;
|
|
|
|
protocol_error:
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Process a DATA packet, adding the packet to the Rx ring. The caller's
|
|
* packet ref must be passed on or discarded.
|
|
*/
|
|
static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
|
|
{
|
|
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
|
|
rxrpc_serial_t serial = sp->hdr.serial;
|
|
rxrpc_seq_t seq0 = sp->hdr.seq;
|
|
|
|
_enter("{%x,%x,%x},{%u,%x}",
|
|
call->ackr_window, call->ackr_wtop, call->rx_highest_seq,
|
|
skb->len, seq0);
|
|
|
|
if (__rxrpc_call_is_complete(call))
|
|
return;
|
|
|
|
switch (__rxrpc_call_state(call)) {
|
|
case RXRPC_CALL_CLIENT_SEND_REQUEST:
|
|
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
|
|
/* Received data implicitly ACKs all of the request
|
|
* packets we sent when we're acting as a client.
|
|
*/
|
|
if (!rxrpc_receiving_reply(call))
|
|
goto out_notify;
|
|
break;
|
|
|
|
case RXRPC_CALL_SERVER_RECV_REQUEST: {
|
|
unsigned long timo = READ_ONCE(call->next_req_timo);
|
|
unsigned long now, expect_req_by;
|
|
|
|
if (timo) {
|
|
now = jiffies;
|
|
expect_req_by = now + timo;
|
|
WRITE_ONCE(call->expect_req_by, expect_req_by);
|
|
rxrpc_reduce_call_timer(call, expect_req_by, now,
|
|
rxrpc_timer_set_for_idle);
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (!rxrpc_input_split_jumbo(call, skb)) {
|
|
rxrpc_proto_abort(call, sp->hdr.seq, rxrpc_badmsg_bad_jumbo);
|
|
goto out_notify;
|
|
}
|
|
return;
|
|
|
|
out_notify:
|
|
trace_rxrpc_notify_socket(call->debug_id, serial);
|
|
rxrpc_notify_socket(call);
|
|
_leave(" [queued]");
|
|
}
|
|
|
|
/*
|
|
* See if there's a cached RTT probe to complete.
|
|
*/
|
|
static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
|
|
ktime_t resp_time,
|
|
rxrpc_serial_t acked_serial,
|
|
rxrpc_serial_t ack_serial,
|
|
enum rxrpc_rtt_rx_trace type)
|
|
{
|
|
rxrpc_serial_t orig_serial;
|
|
unsigned long avail;
|
|
ktime_t sent_at;
|
|
bool matched = false;
|
|
int i;
|
|
|
|
avail = READ_ONCE(call->rtt_avail);
|
|
smp_rmb(); /* Read avail bits before accessing data. */
|
|
|
|
for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) {
|
|
if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
|
|
continue;
|
|
|
|
sent_at = call->rtt_sent_at[i];
|
|
orig_serial = call->rtt_serial[i];
|
|
|
|
if (orig_serial == acked_serial) {
|
|
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
|
|
smp_mb(); /* Read data before setting avail bit */
|
|
set_bit(i, &call->rtt_avail);
|
|
if (type != rxrpc_rtt_rx_cancel)
|
|
rxrpc_peer_add_rtt(call, type, i, acked_serial, ack_serial,
|
|
sent_at, resp_time);
|
|
else
|
|
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_cancel, i,
|
|
orig_serial, acked_serial, 0, 0);
|
|
matched = true;
|
|
}
|
|
|
|
/* If a later serial is being acked, then mark this slot as
|
|
* being available.
|
|
*/
|
|
if (after(acked_serial, orig_serial)) {
|
|
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i,
|
|
orig_serial, acked_serial, 0, 0);
|
|
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
|
|
smp_wmb();
|
|
set_bit(i, &call->rtt_avail);
|
|
}
|
|
}
|
|
|
|
if (!matched)
|
|
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0);
|
|
}
|
|
|
|
/*
|
|
* Process the extra information that may be appended to an ACK packet
|
|
*/
|
|
static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
|
|
struct rxrpc_ackinfo *ackinfo)
|
|
{
|
|
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
|
|
struct rxrpc_peer *peer;
|
|
unsigned int mtu;
|
|
bool wake = false;
|
|
u32 rwind = ntohl(ackinfo->rwind);
|
|
|
|
if (rwind > RXRPC_TX_MAX_WINDOW)
|
|
rwind = RXRPC_TX_MAX_WINDOW;
|
|
if (call->tx_winsize != rwind) {
|
|
if (rwind > call->tx_winsize)
|
|
wake = true;
|
|
trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake);
|
|
call->tx_winsize = rwind;
|
|
}
|
|
|
|
if (call->cong_ssthresh > rwind)
|
|
call->cong_ssthresh = rwind;
|
|
|
|
mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
|
|
|
|
peer = call->peer;
|
|
if (mtu < peer->maxdata) {
|
|
spin_lock(&peer->lock);
|
|
peer->maxdata = mtu;
|
|
peer->mtu = mtu + peer->hdrsize;
|
|
spin_unlock(&peer->lock);
|
|
}
|
|
|
|
if (wake)
|
|
wake_up(&call->waitq);
|
|
}
|
|
|
|
/*
|
|
* Process individual soft ACKs.
|
|
*
|
|
* Each ACK in the array corresponds to one packet and can be either an ACK or
|
|
* a NAK. If we get find an explicitly NAK'd packet we resend immediately;
|
|
* packets that lie beyond the end of the ACK list are scheduled for resend by
|
|
* the timer on the basis that the peer might just not have processed them at
|
|
* the time the ACK was sent.
|
|
*/
|
|
static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
|
|
rxrpc_seq_t seq, int nr_acks,
|
|
struct rxrpc_ack_summary *summary)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < nr_acks; i++) {
|
|
if (acks[i] == RXRPC_ACK_TYPE_ACK) {
|
|
summary->nr_acks++;
|
|
summary->nr_new_acks++;
|
|
} else {
|
|
if (!summary->saw_nacks &&
|
|
call->acks_lowest_nak != seq + i) {
|
|
call->acks_lowest_nak = seq + i;
|
|
summary->new_low_nack = true;
|
|
}
|
|
summary->saw_nacks = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Return true if the ACK is valid - ie. it doesn't appear to have regressed
|
|
* with respect to the ack state conveyed by preceding ACKs.
|
|
*/
|
|
static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
|
|
rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt)
|
|
{
|
|
rxrpc_seq_t base = READ_ONCE(call->acks_first_seq);
|
|
|
|
if (after(first_pkt, base))
|
|
return true; /* The window advanced */
|
|
|
|
if (before(first_pkt, base))
|
|
return false; /* firstPacket regressed */
|
|
|
|
if (after_eq(prev_pkt, call->acks_prev_seq))
|
|
return true; /* previousPacket hasn't regressed. */
|
|
|
|
/* Some rx implementations put a serial number in previousPacket. */
|
|
if (after_eq(prev_pkt, base + call->tx_winsize))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Process an ACK packet.
|
|
*
|
|
* ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
|
|
* in the ACK array. Anything before that is hard-ACK'd and may be discarded.
|
|
*
|
|
* A hard-ACK means that a packet has been processed and may be discarded; a
|
|
* soft-ACK means that the packet may be discarded and retransmission
|
|
* requested. A phase is complete when all packets are hard-ACK'd.
|
|
*/
|
|
static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
|
|
{
|
|
struct rxrpc_ack_summary summary = { 0 };
|
|
struct rxrpc_ackpacket ack;
|
|
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
|
|
struct rxrpc_ackinfo info;
|
|
rxrpc_serial_t ack_serial, acked_serial;
|
|
rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
|
|
int nr_acks, offset, ioffset;
|
|
|
|
_enter("");
|
|
|
|
offset = sizeof(struct rxrpc_wire_header);
|
|
if (skb_copy_bits(skb, offset, &ack, sizeof(ack)) < 0)
|
|
return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack);
|
|
offset += sizeof(ack);
|
|
|
|
ack_serial = sp->hdr.serial;
|
|
acked_serial = ntohl(ack.serial);
|
|
first_soft_ack = ntohl(ack.firstPacket);
|
|
prev_pkt = ntohl(ack.previousPacket);
|
|
hard_ack = first_soft_ack - 1;
|
|
nr_acks = ack.nAcks;
|
|
summary.ack_reason = (ack.reason < RXRPC_ACK__INVALID ?
|
|
ack.reason : RXRPC_ACK__INVALID);
|
|
|
|
trace_rxrpc_rx_ack(call, ack_serial, acked_serial,
|
|
first_soft_ack, prev_pkt,
|
|
summary.ack_reason, nr_acks);
|
|
rxrpc_inc_stat(call->rxnet, stat_rx_acks[ack.reason]);
|
|
|
|
switch (ack.reason) {
|
|
case RXRPC_ACK_PING_RESPONSE:
|
|
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
|
|
rxrpc_rtt_rx_ping_response);
|
|
break;
|
|
case RXRPC_ACK_REQUESTED:
|
|
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
|
|
rxrpc_rtt_rx_requested_ack);
|
|
break;
|
|
default:
|
|
if (acked_serial != 0)
|
|
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
|
|
rxrpc_rtt_rx_cancel);
|
|
break;
|
|
}
|
|
|
|
if (ack.reason == RXRPC_ACK_PING) {
|
|
rxrpc_send_ACK(call, RXRPC_ACK_PING_RESPONSE, ack_serial,
|
|
rxrpc_propose_ack_respond_to_ping);
|
|
} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
|
|
rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, ack_serial,
|
|
rxrpc_propose_ack_respond_to_ack);
|
|
}
|
|
|
|
/* If we get an EXCEEDS_WINDOW ACK from the server, it probably
|
|
* indicates that the client address changed due to NAT. The server
|
|
* lost the call because it switched to a different peer.
|
|
*/
|
|
if (unlikely(ack.reason == RXRPC_ACK_EXCEEDS_WINDOW) &&
|
|
first_soft_ack == 1 &&
|
|
prev_pkt == 0 &&
|
|
rxrpc_is_client_call(call)) {
|
|
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
|
|
0, -ENETRESET);
|
|
return;
|
|
}
|
|
|
|
/* If we get an OUT_OF_SEQUENCE ACK from the server, that can also
|
|
* indicate a change of address. However, we can retransmit the call
|
|
* if we still have it buffered to the beginning.
|
|
*/
|
|
if (unlikely(ack.reason == RXRPC_ACK_OUT_OF_SEQUENCE) &&
|
|
first_soft_ack == 1 &&
|
|
prev_pkt == 0 &&
|
|
call->acks_hard_ack == 0 &&
|
|
rxrpc_is_client_call(call)) {
|
|
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
|
|
0, -ENETRESET);
|
|
return;
|
|
}
|
|
|
|
/* Discard any out-of-order or duplicate ACKs (outside lock). */
|
|
if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
|
|
trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
|
|
first_soft_ack, call->acks_first_seq,
|
|
prev_pkt, call->acks_prev_seq);
|
|
return;
|
|
}
|
|
|
|
info.rxMTU = 0;
|
|
ioffset = offset + nr_acks + 3;
|
|
if (skb->len >= ioffset + sizeof(info) &&
|
|
skb_copy_bits(skb, ioffset, &info, sizeof(info)) < 0)
|
|
return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack_info);
|
|
|
|
if (nr_acks > 0)
|
|
skb_condense(skb);
|
|
|
|
call->acks_latest_ts = skb->tstamp;
|
|
call->acks_first_seq = first_soft_ack;
|
|
call->acks_prev_seq = prev_pkt;
|
|
|
|
switch (ack.reason) {
|
|
case RXRPC_ACK_PING:
|
|
break;
|
|
default:
|
|
if (after(acked_serial, call->acks_highest_serial))
|
|
call->acks_highest_serial = acked_serial;
|
|
break;
|
|
}
|
|
|
|
/* Parse rwind and mtu sizes if provided. */
|
|
if (info.rxMTU)
|
|
rxrpc_input_ackinfo(call, skb, &info);
|
|
|
|
if (first_soft_ack == 0)
|
|
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_zero);
|
|
|
|
/* Ignore ACKs unless we are or have just been transmitting. */
|
|
switch (__rxrpc_call_state(call)) {
|
|
case RXRPC_CALL_CLIENT_SEND_REQUEST:
|
|
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
|
|
case RXRPC_CALL_SERVER_SEND_REPLY:
|
|
case RXRPC_CALL_SERVER_AWAIT_ACK:
|
|
break;
|
|
default:
|
|
return;
|
|
}
|
|
|
|
if (before(hard_ack, call->acks_hard_ack) ||
|
|
after(hard_ack, call->tx_top))
|
|
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_outside_window);
|
|
if (nr_acks > call->tx_top - hard_ack)
|
|
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_sack_overflow);
|
|
|
|
if (after(hard_ack, call->acks_hard_ack)) {
|
|
if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
|
|
rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ack);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (nr_acks > 0) {
|
|
if (offset > (int)skb->len - nr_acks)
|
|
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_short_sack);
|
|
rxrpc_input_soft_acks(call, skb->data + offset, first_soft_ack,
|
|
nr_acks, &summary);
|
|
}
|
|
|
|
if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) &&
|
|
summary.nr_acks == call->tx_top - hard_ack &&
|
|
rxrpc_is_client_call(call))
|
|
rxrpc_propose_ping(call, ack_serial,
|
|
rxrpc_propose_ack_ping_for_lost_reply);
|
|
|
|
rxrpc_congestion_management(call, skb, &summary, acked_serial);
|
|
}
|
|
|
|
/*
|
|
* Process an ACKALL packet.
|
|
*/
|
|
static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
|
|
{
|
|
struct rxrpc_ack_summary summary = { 0 };
|
|
|
|
if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
|
|
rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ackall);
|
|
}
|
|
|
|
/*
|
|
* Process an ABORT packet directed at a call.
|
|
*/
|
|
static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
|
|
{
|
|
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
|
|
|
|
trace_rxrpc_rx_abort(call, sp->hdr.serial, skb->priority);
|
|
|
|
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
|
|
skb->priority, -ECONNABORTED);
|
|
}
|
|
|
|
/*
|
|
* Process an incoming call packet.
|
|
*/
|
|
void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb)
|
|
{
|
|
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
|
|
unsigned long timo;
|
|
|
|
_enter("%p,%p", call, skb);
|
|
|
|
if (sp->hdr.serviceId != call->dest_srx.srx_service)
|
|
call->dest_srx.srx_service = sp->hdr.serviceId;
|
|
if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
|
|
call->rx_serial = sp->hdr.serial;
|
|
if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
|
|
set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
|
|
|
|
timo = READ_ONCE(call->next_rx_timo);
|
|
if (timo) {
|
|
unsigned long now = jiffies, expect_rx_by;
|
|
|
|
expect_rx_by = now + timo;
|
|
WRITE_ONCE(call->expect_rx_by, expect_rx_by);
|
|
rxrpc_reduce_call_timer(call, expect_rx_by, now,
|
|
rxrpc_timer_set_for_normal);
|
|
}
|
|
|
|
switch (sp->hdr.type) {
|
|
case RXRPC_PACKET_TYPE_DATA:
|
|
return rxrpc_input_data(call, skb);
|
|
|
|
case RXRPC_PACKET_TYPE_ACK:
|
|
return rxrpc_input_ack(call, skb);
|
|
|
|
case RXRPC_PACKET_TYPE_BUSY:
|
|
/* Just ignore BUSY packets from the server; the retry and
|
|
* lifespan timers will take care of business. BUSY packets
|
|
* from the client don't make sense.
|
|
*/
|
|
return;
|
|
|
|
case RXRPC_PACKET_TYPE_ABORT:
|
|
return rxrpc_input_abort(call, skb);
|
|
|
|
case RXRPC_PACKET_TYPE_ACKALL:
|
|
return rxrpc_input_ackall(call, skb);
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Handle a new service call on a channel implicitly completing the preceding
|
|
* call on that channel. This does not apply to client conns.
|
|
*
|
|
* TODO: If callNumber > call_id + 1, renegotiate security.
|
|
*/
|
|
void rxrpc_implicit_end_call(struct rxrpc_call *call, struct sk_buff *skb)
|
|
{
|
|
switch (__rxrpc_call_state(call)) {
|
|
case RXRPC_CALL_SERVER_AWAIT_ACK:
|
|
rxrpc_call_completed(call);
|
|
fallthrough;
|
|
case RXRPC_CALL_COMPLETE:
|
|
break;
|
|
default:
|
|
rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ESHUTDOWN,
|
|
rxrpc_eproto_improper_term);
|
|
trace_rxrpc_improper_term(call);
|
|
break;
|
|
}
|
|
|
|
rxrpc_input_call_event(call, skb);
|
|
}
|