mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
synced 2024-12-28 16:52:18 +00:00
eeaedc5449
Implement path-MTU probing (along the lines of RFC8899) by padding some of the PING ACKs we send. PING ACKs get their own individual responses quite apart from the acking of data (though, as ACKs, they fulfil that role also). The probing concentrates on packet sizes that correspond how many subpackets can be stuffed inside a jumbo packet as jumbo DATA packets are just aggregations of individual DATA packets and can be split easily for retransmission purposes. If we want to perform probing, we advertise this by setting the maximum number of jumbo subpackets to 0 in the ack trailer when we send an ACK and see if the peer is also advertising the service. This is interpreted by non-supporting Rx stacks as an indication that jumbo packets aren't supported. The MTU sizes advertised in the ACK trailer AF_RXRPC transmits are pegged at a maximum of 1444 unless pmtud is supported by both sides. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20241204074710.990092-10-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
63 lines
1.9 KiB
C
63 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* Miscellaneous bits
|
|
*
|
|
* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <net/sock.h>
|
|
#include <net/af_rxrpc.h>
|
|
#include "ar-internal.h"
|
|
|
|
/*
|
|
* The maximum listening backlog queue size that may be set on a socket by
|
|
* listen().
|
|
*/
|
|
unsigned int rxrpc_max_backlog __read_mostly = 10;
|
|
|
|
/*
|
|
* How long to wait before scheduling an ACK with subtype DELAY (in ms).
|
|
*
|
|
* We use this when we've received new data packets. If those packets aren't
|
|
* all consumed within this time we will send a DELAY ACK if an ACK was not
|
|
* requested to let the sender know it doesn't need to resend.
|
|
*/
|
|
unsigned long rxrpc_soft_ack_delay = 1000;
|
|
|
|
/*
|
|
* How long to wait before scheduling an ACK with subtype IDLE (in ms).
|
|
*
|
|
* We use this when we've consumed some previously soft-ACK'd packets when
|
|
* further packets aren't immediately received to decide when to send an IDLE
|
|
* ACK let the other end know that it can free up its Tx buffer space.
|
|
*/
|
|
unsigned long rxrpc_idle_ack_delay = 500;
|
|
|
|
/*
|
|
* Receive window size in packets. This indicates the maximum number of
|
|
* unconsumed received packets we're willing to retain in memory. Once this
|
|
* limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
|
|
* packets.
|
|
*/
|
|
unsigned int rxrpc_rx_window_size = 255;
|
|
|
|
/*
|
|
* Maximum Rx MTU size. This indicates to the sender the size of jumbo packet
|
|
* made by gluing normal packets together that we're willing to handle.
|
|
*/
|
|
unsigned int rxrpc_rx_mtu = RXRPC_JUMBO(46);
|
|
|
|
/*
|
|
* The maximum number of fragments in a received jumbo packet that we tell the
|
|
* sender that we're willing to handle.
|
|
*/
|
|
unsigned int rxrpc_rx_jumbo_max = 46;
|
|
|
|
#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
|
|
/*
|
|
* The delay to inject into packet reception.
|
|
*/
|
|
unsigned long rxrpc_inject_rx_delay;
|
|
#endif
|