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 */
32 struct 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 */
45 struct tfrc_loss_hist {
46 struct tfrc_loss_interval *ring[LIH_SIZE];
47 u8 counter;
48 u32 i_mean;
49 };
50
tfrc_lh_init(struct tfrc_loss_hist * lh)51 static inline void tfrc_lh_init(struct tfrc_loss_hist *lh)
52 {
53 memset(lh, 0, sizeof(struct tfrc_loss_hist));
54 }
55
tfrc_lh_is_initialised(struct tfrc_loss_hist * lh)56 static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh)
57 {
58 return lh->counter > 0;
59 }
60
tfrc_lh_length(struct tfrc_loss_hist * lh)61 static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh)
62 {
63 return min(lh->counter, (u8)LIH_SIZE);
64 }
65
66 struct tfrc_rx_hist;
67
68 extern int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *,
69 u32 (*first_li)(struct sock *), struct sock *);
70 extern u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *);
71 extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh);
72
73 #endif /* _DCCP_LI_HIST_ */
74