net/rxrpc/misc.c

   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 }