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 */ 34 struct 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 */ 47 struct tfrc_loss_hist { 48 struct tfrc_loss_interval *ring[LIH_SIZE]; 49 u8 counter; 50 u32 i_mean; 51 }; 52 53 static inline void tfrc_lh_init(struct tfrc_loss_hist *lh) 54 { 55 memset(lh, 0, sizeof(struct tfrc_loss_hist)); 56 } 57 58 static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh) 59 { 60 return lh->counter > 0; 61 } 62 63 static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh) 64 { 65 return min(lh->counter, (u8)LIH_SIZE); 66 } 67 68 struct tfrc_rx_hist; 69 70 extern int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *, 71 u32 (*first_li)(struct sock *), struct sock *); 72 extern u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *); 73 extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh); 74 75 #endif /* _DCCP_LI_HIST_ */ 76