1 /* Miscellaneous bits
2  *
3  * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public Licence
8  * as published by the Free Software Foundation; either version
9  * 2 of the Licence, or (at your option) any later version.
10  */
11 
12 #include <linux/kernel.h>
13 #include <net/sock.h>
14 #include <net/af_rxrpc.h>
15 #include "ar-internal.h"
16 
17 /*
18  * The maximum listening backlog queue size that may be set on a socket by
19  * listen().
20  */
21 unsigned int rxrpc_max_backlog __read_mostly = 10;
22 
23 /*
24  * How long to wait before scheduling ACK generation after seeing a
25  * packet with RXRPC_REQUEST_ACK set (in jiffies).
26  */
27 unsigned long rxrpc_requested_ack_delay = 1;
28 
29 /*
30  * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
31  *
32  * We use this when we've received new data packets.  If those packets aren't
33  * all consumed within this time we will send a DELAY ACK if an ACK was not
34  * requested to let the sender know it doesn't need to resend.
35  */
36 unsigned long rxrpc_soft_ack_delay = HZ;
37 
38 /*
39  * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
40  *
41  * We use this when we've consumed some previously soft-ACK'd packets when
42  * further packets aren't immediately received to decide when to send an IDLE
43  * ACK let the other end know that it can free up its Tx buffer space.
44  */
45 unsigned long rxrpc_idle_ack_delay = HZ / 2;
46 
47 /*
48  * Receive window size in packets.  This indicates the maximum number of
49  * unconsumed received packets we're willing to retain in memory.  Once this
50  * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
51  * packets.
52  */
53 unsigned int rxrpc_rx_window_size = RXRPC_INIT_RX_WINDOW_SIZE;
54 #if (RXRPC_RXTX_BUFF_SIZE - 1) < RXRPC_INIT_RX_WINDOW_SIZE
55 #error Need to reduce RXRPC_INIT_RX_WINDOW_SIZE
56 #endif
57 
58 /*
59  * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
60  * made by gluing normal packets together that we're willing to handle.
61  */
62 unsigned int rxrpc_rx_mtu = 5692;
63 
64 /*
65  * The maximum number of fragments in a received jumbo packet that we tell the
66  * sender that we're willing to handle.
67  */
68 unsigned int rxrpc_rx_jumbo_max = 4;
69 
70 /*
71  * Time till packet resend (in milliseconds).
72  */
73 unsigned long rxrpc_resend_timeout = 4 * HZ;
74 
75 const s8 rxrpc_ack_priority[] = {
76 	[0]				= 0,
77 	[RXRPC_ACK_DELAY]		= 1,
78 	[RXRPC_ACK_REQUESTED]		= 2,
79 	[RXRPC_ACK_IDLE]		= 3,
80 	[RXRPC_ACK_DUPLICATE]		= 4,
81 	[RXRPC_ACK_OUT_OF_SEQUENCE]	= 5,
82 	[RXRPC_ACK_EXCEEDS_WINDOW]	= 6,
83 	[RXRPC_ACK_NOSPACE]		= 7,
84 	[RXRPC_ACK_PING_RESPONSE]	= 8,
85 };
86