1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Miscellaneous bits
3  *
4  * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/kernel.h>
9 #include <net/sock.h>
10 #include <net/af_rxrpc.h>
11 #include "ar-internal.h"
12 
13 /*
14  * The maximum listening backlog queue size that may be set on a socket by
15  * listen().
16  */
17 unsigned int rxrpc_max_backlog __read_mostly = 10;
18 
19 /*
20  * How long to wait before scheduling ACK generation after seeing a
21  * packet with RXRPC_REQUEST_ACK set (in jiffies).
22  */
23 unsigned long rxrpc_requested_ack_delay = 1;
24 
25 /*
26  * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
27  *
28  * We use this when we've received new data packets.  If those packets aren't
29  * all consumed within this time we will send a DELAY ACK if an ACK was not
30  * requested to let the sender know it doesn't need to resend.
31  */
32 unsigned long rxrpc_soft_ack_delay = HZ;
33 
34 /*
35  * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
36  *
37  * We use this when we've consumed some previously soft-ACK'd packets when
38  * further packets aren't immediately received to decide when to send an IDLE
39  * ACK let the other end know that it can free up its Tx buffer space.
40  */
41 unsigned long rxrpc_idle_ack_delay = HZ / 2;
42 
43 /*
44  * Receive window size in packets.  This indicates the maximum number of
45  * unconsumed received packets we're willing to retain in memory.  Once this
46  * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
47  * packets.
48  */
49 unsigned int rxrpc_rx_window_size = RXRPC_INIT_RX_WINDOW_SIZE;
50 #if (RXRPC_RXTX_BUFF_SIZE - 1) < RXRPC_INIT_RX_WINDOW_SIZE
51 #error Need to reduce RXRPC_INIT_RX_WINDOW_SIZE
52 #endif
53 
54 /*
55  * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
56  * made by gluing normal packets together that we're willing to handle.
57  */
58 unsigned int rxrpc_rx_mtu = 5692;
59 
60 /*
61  * The maximum number of fragments in a received jumbo packet that we tell the
62  * sender that we're willing to handle.
63  */
64 unsigned int rxrpc_rx_jumbo_max = 4;
65 
66 const s8 rxrpc_ack_priority[] = {
67 	[0]				= 0,
68 	[RXRPC_ACK_DELAY]		= 1,
69 	[RXRPC_ACK_REQUESTED]		= 2,
70 	[RXRPC_ACK_IDLE]		= 3,
71 	[RXRPC_ACK_DUPLICATE]		= 4,
72 	[RXRPC_ACK_OUT_OF_SEQUENCE]	= 5,
73 	[RXRPC_ACK_EXCEEDS_WINDOW]	= 6,
74 	[RXRPC_ACK_NOSPACE]		= 7,
75 	[RXRPC_ACK_PING_RESPONSE]	= 8,
76 };
77