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

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