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