xref: /linux/net/rxrpc/misc.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
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 int 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 int rxrpc_soft_ack_delay = 1 * 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 int rxrpc_idle_ack_delay = 0.5 * HZ;
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 = 32;
54 
55 /*
56  * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
57  * made by gluing normal packets together that we're willing to handle.
58  */
59 unsigned int rxrpc_rx_mtu = 5692;
60 
61 /*
62  * The maximum number of fragments in a received jumbo packet that we tell the
63  * sender that we're willing to handle.
64  */
65 unsigned int rxrpc_rx_jumbo_max = 4;
66 
67 const char *const rxrpc_pkts[] = {
68 	"?00",
69 	"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
70 	"?09", "?10", "?11", "?12", "VERSION", "?14", "?15"
71 };
72 
73 const s8 rxrpc_ack_priority[] = {
74 	[0]				= 0,
75 	[RXRPC_ACK_DELAY]		= 1,
76 	[RXRPC_ACK_REQUESTED]		= 2,
77 	[RXRPC_ACK_IDLE]		= 3,
78 	[RXRPC_ACK_PING_RESPONSE]	= 4,
79 	[RXRPC_ACK_DUPLICATE]		= 5,
80 	[RXRPC_ACK_OUT_OF_SEQUENCE]	= 6,
81 	[RXRPC_ACK_EXCEEDS_WINDOW]	= 7,
82 	[RXRPC_ACK_NOSPACE]		= 8,
83 };
84 
85 const char *rxrpc_acks(u8 reason)
86 {
87 	static const char *const str[] = {
88 		"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
89 		"IDL", "-?-"
90 	};
91 
92 	if (reason >= ARRAY_SIZE(str))
93 		reason = ARRAY_SIZE(str) - 1;
94 	return str[reason];
95 }
96