LXR linux/net/dccp/ccids/lib/loss

   1#ifndef _DCCP_LI_HIST_
   2#define _DCCP_LI_HIST_
   3/*
   4 *  net/dccp/ccids/lib/loss_interval.h
   5 *
   6 *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
   7 *  Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
   8 *  Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz>
   9 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  10 *
  11 *  This program is free software; you can redistribute it and/or modify it
  12 *  under the terms of the GNU General Public License as published by the Free
  13 *  Software Foundation; either version 2 of the License, or (at your option)
  14 *  any later version.
  15 */
  16#include <linux/ktime.h>
  17#include <linux/list.h>
  18#include <linux/slab.h>
  19
  20/*
  21 * Number of loss intervals (RFC 4342, 8.6.1). The history size is one more than
  22 * NINTERVAL, since the `open' interval I_0 is always stored as the first entry.
  23 */
  24#define NINTERVAL       8
  25#define LIH_SIZE        (NINTERVAL + 1)
  26
  27/**
  28 *  tfrc_loss_interval  -  Loss history record for TFRC-based protocols
  29 *  @li_seqno:          Highest received seqno before the start of loss
  30 *  @li_ccval:          The CCVal belonging to @li_seqno
  31 *  @li_is_closed:      Whether @li_seqno is older than 1 RTT
  32 *  @li_length:         Loss interval sequence length
  33 */
  34struct tfrc_loss_interval {
  35        u64              li_seqno:48,
  36                         li_ccval:4,
  37                         li_is_closed:1;
  38        u32              li_length;
  39};
  40
  41/**
  42 *  tfrc_loss_hist  -  Loss record database
  43 *  @ring:      Circular queue managed in LIFO manner
  44 *  @counter:   Current count of entries (can be more than %LIH_SIZE)
  45 *  @i_mean:    Current Average Loss Interval [RFC 3448, 5.4]
  46 */
  47struct tfrc_loss_hist {
  48        struct tfrc_loss_interval       *ring[LIH_SIZE];
  49        u8                              counter;
  50        u32                             i_mean;
  51};
  52
  53static inline void tfrc_lh_init(struct tfrc_loss_hist *lh)
  54{
  55        memset(lh, 0, sizeof(struct tfrc_loss_hist));
  56}
  57
  58static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh)
  59{
  60        return lh->counter > 0;
  61}
  62
  63static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh)
  64{
  65        return min(lh->counter, (u8)LIH_SIZE);
  66}
  67
  68struct tfrc_rx_hist;
  69
  70extern int  tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *,
  71                                 u32 (*first_li)(struct sock *), struct sock *);
  72extern u8   tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *);
  73extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh);
  74
  75#endif /* _DCCP_LI_HIST_ */
  76