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 51 static inline void tfrc_lh_init(struct tfrc_loss_hist *lh) 52 { 53 memset(lh, 0, sizeof(struct tfrc_loss_hist)); 54 } 55 56 static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh) 57 { 58 return lh->counter > 0; 59 } 60 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