xref: /linux/net/rxrpc/misc.c (revision bb9707077b4ee5f77bc9939b057ff8a0d410296f)
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  * How long to wait before scheduling ACK generation after seeing a
19  * packet with RXRPC_REQUEST_ACK set (in jiffies).
20  */
21 unsigned int rxrpc_requested_ack_delay = 1;
22 
23 /*
24  * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
25  *
26  * We use this when we've received new data packets.  If those packets aren't
27  * all consumed within this time we will send a DELAY ACK if an ACK was not
28  * requested to let the sender know it doesn't need to resend.
29  */
30 unsigned int rxrpc_soft_ack_delay = 1 * HZ;
31 
32 /*
33  * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
34  *
35  * We use this when we've consumed some previously soft-ACK'd packets when
36  * further packets aren't immediately received to decide when to send an IDLE
37  * ACK let the other end know that it can free up its Tx buffer space.
38  */
39 unsigned int rxrpc_idle_ack_delay = 0.5 * HZ;
40 
41 /*
42  * Receive window size in packets.  This indicates the maximum number of
43  * unconsumed received packets we're willing to retain in memory.  Once this
44  * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
45  * packets.
46  */
47 unsigned int rxrpc_rx_window_size = 32;
48 
49 /*
50  * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
51  * made by gluing normal packets together that we're willing to handle.
52  */
53 unsigned int rxrpc_rx_mtu = 5692;
54 
55 /*
56  * The maximum number of fragments in a received jumbo packet that we tell the
57  * sender that we're willing to handle.
58  */
59 unsigned int rxrpc_rx_jumbo_max = 4;
60 
61 const char *const rxrpc_pkts[] = {
62 	"?00",
63 	"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
64 	"?09", "?10", "?11", "?12", "VERSION", "?14", "?15"
65 };
66 
67 const s8 rxrpc_ack_priority[] = {
68 	[0]				= 0,
69 	[RXRPC_ACK_DELAY]		= 1,
70 	[RXRPC_ACK_REQUESTED]		= 2,
71 	[RXRPC_ACK_IDLE]		= 3,
72 	[RXRPC_ACK_PING_RESPONSE]	= 4,
73 	[RXRPC_ACK_DUPLICATE]		= 5,
74 	[RXRPC_ACK_OUT_OF_SEQUENCE]	= 6,
75 	[RXRPC_ACK_EXCEEDS_WINDOW]	= 7,
76 	[RXRPC_ACK_NOSPACE]		= 8,
77 };
78 
79 const char *rxrpc_acks(u8 reason)
80 {
81 	static const char *const str[] = {
82 		"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
83 		"IDL", "-?-"
84 	};
85 
86 	if (reason >= ARRAY_SIZE(str))
87 		reason = ARRAY_SIZE(str) - 1;
88 	return str[reason];
89 }
90