8a9c7e92e0
A ringbuffer-based implementation of loss interval history is easier to maintain, allocate, and update. The `swap' routine to keep the RX history sorted is due to and was written by Arnaldo Carvalho de Melo, simplifying an earlier macro-based variant. Details: * access to the Loss Interval Records via macro wrappers (with safety checks); * simplified, on-demand allocation of entries (no extra memory consumption on lossless links); cache allocation is local to the module / exported as service; * provision of RFC-compliant algorithm to re-compute average loss interval; * provision of comprehensive, new loss detection algorithm - support for all cases of loss, including re-ordered/duplicate packets; - waiting for NDUPACK=3 packets to fill the hole; - updating loss records when a late-arriving packet fills a hole. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
83 lines
2.6 KiB
C
83 lines
2.6 KiB
C
#ifndef _DCCP_LI_HIST_
|
|
#define _DCCP_LI_HIST_
|
|
/*
|
|
* net/dccp/ccids/lib/loss_interval.h
|
|
*
|
|
* Copyright (c) 2007 The University of Aberdeen, Scotland, UK
|
|
* Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
|
|
* Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz>
|
|
* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
|
* any later version.
|
|
*/
|
|
#include <linux/ktime.h>
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
|
|
/*
|
|
* Number of loss intervals (RFC 4342, 8.6.1). The history size is one more than
|
|
* NINTERVAL, since the `open' interval I_0 is always stored as the first entry.
|
|
*/
|
|
#define NINTERVAL 8
|
|
#define LIH_SIZE (NINTERVAL + 1)
|
|
|
|
/**
|
|
* tfrc_loss_interval - Loss history record for TFRC-based protocols
|
|
* @li_seqno: Highest received seqno before the start of loss
|
|
* @li_ccval: The CCVal belonging to @li_seqno
|
|
* @li_is_closed: Whether @li_seqno is older than 1 RTT
|
|
* @li_length: Loss interval sequence length
|
|
*/
|
|
struct tfrc_loss_interval {
|
|
u64 li_seqno:48,
|
|
li_ccval:4,
|
|
li_is_closed:1;
|
|
u32 li_length;
|
|
};
|
|
|
|
/**
|
|
* tfrc_loss_hist - Loss record database
|
|
* @ring: Circular queue managed in LIFO manner
|
|
* @counter: Current count of entries (can be more than %LIH_SIZE)
|
|
* @i_mean: Current Average Loss Interval [RFC 3448, 5.4]
|
|
*/
|
|
struct tfrc_loss_hist {
|
|
struct tfrc_loss_interval *ring[LIH_SIZE];
|
|
u8 counter;
|
|
u32 i_mean;
|
|
};
|
|
|
|
static inline void tfrc_lh_init(struct tfrc_loss_hist *lh)
|
|
{
|
|
memset(lh, 0, sizeof(struct tfrc_loss_hist));
|
|
}
|
|
|
|
static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh)
|
|
{
|
|
return lh->counter > 0;
|
|
}
|
|
|
|
static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh)
|
|
{
|
|
return min(lh->counter, (u8)LIH_SIZE);
|
|
}
|
|
|
|
extern void dccp_li_hist_purge(struct list_head *list);
|
|
struct tfrc_rx_hist;
|
|
extern int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *,
|
|
u32 (*first_li)(struct sock *), struct sock *);
|
|
extern u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *);
|
|
extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh);
|
|
|
|
extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);
|
|
|
|
extern void dccp_li_update_li(struct sock *sk,
|
|
struct list_head *li_hist_list,
|
|
struct list_head *hist_list,
|
|
ktime_t last_feedback, u16 s,
|
|
u32 bytes_recv, u32 previous_x_recv,
|
|
u64 seq_loss, u8 win_loss);
|
|
#endif /* _DCCP_LI_HIST_ */
|