/* Management of Tx window, Tx resend, ACKs and out-of-sequence reception
*
* Copyright (C) 2007 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 License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/circ_buf.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/udp.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* How long to wait before scheduling ACK generation after seeing a
* packet with RXRPC_REQUEST_ACK set (in jiffies).
*/
unsigned 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 rxrpc_soft_ack_delay = 1 * 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 rxrpc_idle_ack_delay = 0.5 * HZ;
/*
* 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 rxrpc_rx_window_size = 32;
/*
* 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 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 rxrpc_rx_jumbo_max = 4;
static const char *rxrpc_acks(u8 reason)
{
static const char *const str[] = {
"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
"IDL", "-?-"
};
if (reason >= ARRAY_SIZE(str))
reason = ARRAY_SIZE(str) - 1;
return str[reason];
}
static const s8 rxrpc_ack_priority[] = {
[0] = 0,
[RXRPC_ACK_DELAY] = 1,
[RXRPC_ACK_REQUESTED] = 2,
[RXRPC_ACK_IDLE] = 3,
[RXRPC_ACK_PING_RESPONSE] = 4,
[RXRPC_ACK_DUPLICATE] = 5,
[RXRPC_ACK_OUT_OF_SEQUENCE] = 6,
[RXRPC_ACK_EXCEEDS_WINDOW