alistair23-linux/net/rxrpc/misc.c
David Howells a158bdd324 rxrpc: Fix call timeouts
Fix the rxrpc call expiration timeouts and make them settable from
userspace.  By analogy with other rx implementations, there should be three
timeouts:

 (1) "Normal timeout"

     This is set for all calls and is triggered if we haven't received any
     packets from the peer in a while.  It is measured from the last time
     we received any packet on that call.  This is not reset by any
     connection packets (such as CHALLENGE/RESPONSE packets).

     If a service operation takes a long time, the server should generate
     PING ACKs at a duration that's substantially less than the normal
     timeout so is to keep both sides alive.  This is set at 1/6 of normal
     timeout.

 (2) "Idle timeout"

     This is set only for a service call and is triggered if we stop
     receiving the DATA packets that comprise the request data.  It is
     measured from the last time we received a DATA packet.

 (3) "Hard timeout"

     This can be set for a call and specified the maximum lifetime of that
     call.  It should not be specified by default.  Some operations (such
     as volume transfer) take a long time.

Allow userspace to set/change the timeouts on a call with sendmsg, using a
control message:

	RXRPC_SET_CALL_TIMEOUTS

The data to the message is a number of 32-bit words, not all of which need
be given:

	u32 hard_timeout;	/* sec from first packet */
	u32 idle_timeout;	/* msec from packet Rx */
	u32 normal_timeout;	/* msec from data Rx */

This can be set in combination with any other sendmsg() that affects a
call.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00

86 lines
2.6 KiB
C

/* Miscellaneous bits
*
* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#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 ACK generation after seeing a
* packet with RXRPC_REQUEST_ACK set (in jiffies).
*/
unsigned long rxrpc_requested_ack_delay = 1;
/*
* How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
*
* 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 = HZ;
/*
* How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
*
* 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 = HZ / 2;
/*
* 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 = RXRPC_INIT_RX_WINDOW_SIZE;
#if (RXRPC_RXTX_BUFF_SIZE - 1) < RXRPC_INIT_RX_WINDOW_SIZE
#error Need to reduce RXRPC_INIT_RX_WINDOW_SIZE
#endif
/*
* 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 = 5692;
/*
* 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 = 4;
/*
* Time till packet resend (in milliseconds).
*/
unsigned long rxrpc_resend_timeout = 4 * HZ;
const s8 rxrpc_ack_priority[] = {
[0] = 0,
[RXRPC_ACK_DELAY] = 1,
[RXRPC_ACK_REQUESTED] = 2,
[RXRPC_ACK_IDLE] = 3,
[RXRPC_ACK_DUPLICATE] = 4,
[RXRPC_ACK_OUT_OF_SEQUENCE] = 5,
[RXRPC_ACK_EXCEEDS_WINDOW] = 6,
[RXRPC_ACK_NOSPACE] = 7,
[RXRPC_ACK_PING_RESPONSE] = 8,
};