89858ad143
This makes RTAX_RTO_MIN also available to CCID-3, replacing the compile-time RTO lower bound with a per-route tunable value. The original Kconfig option solved the problem that a very low RTT (in the order of HZ) can trigger too frequent and unnecessary reductions of the sending rate. This tunable does not affect the initial RTO value of 2 seconds specified in RFC 5348, section 4.2 and Appendix B. But like the hardcoded Kconfig value, it allows to adapt to network conditions. The same effect as the original Kconfig option of 100ms is now achieved by > ip route replace to unicast 192.168.0.0/24 rto_min 100j dev eth0 (assuming HZ=1000). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
164 lines
5.4 KiB
C
164 lines
5.4 KiB
C
/*
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* Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
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* Copyright (c) 2007 The University of Aberdeen, Scotland, UK
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*
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* An implementation of the DCCP protocol
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*
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* This code has been developed by the University of Waikato WAND
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* research group. For further information please see http://www.wand.net.nz/
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* or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
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*
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* This code also uses code from Lulea University, rereleased as GPL by its
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* authors:
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* Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
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*
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* Changes to meet Linux coding standards, to make it meet latest ccid3 draft
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* and to make it work as a loadable module in the DCCP stack written by
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* Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
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*
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* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#ifndef _DCCP_CCID3_H_
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#define _DCCP_CCID3_H_
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#include <linux/ktime.h>
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#include <linux/list.h>
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#include <linux/types.h>
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#include <linux/tfrc.h>
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#include "lib/tfrc.h"
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#include "../ccid.h"
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/* Two seconds as per RFC 5348, 4.2 */
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#define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC)
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/* In usecs - half the scheduling granularity as per RFC3448 4.6 */
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#define TFRC_OPSYS_HALF_TIME_GRAN (USEC_PER_SEC / (2 * HZ))
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/* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
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#define TFRC_T_MBI 64
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enum ccid3_options {
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TFRC_OPT_LOSS_EVENT_RATE = 192,
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TFRC_OPT_LOSS_INTERVALS = 193,
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TFRC_OPT_RECEIVE_RATE = 194,
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};
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struct ccid3_options_received {
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u64 ccid3or_seqno:48,
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ccid3or_loss_intervals_idx:16;
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u16 ccid3or_loss_intervals_len;
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u32 ccid3or_loss_event_rate;
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u32 ccid3or_receive_rate;
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};
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/* TFRC sender states */
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enum ccid3_hc_tx_states {
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TFRC_SSTATE_NO_SENT = 1,
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TFRC_SSTATE_NO_FBACK,
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TFRC_SSTATE_FBACK,
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TFRC_SSTATE_TERM,
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};
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/**
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* struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
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* @tx_x: Current sending rate in 64 * bytes per second
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* @tx_x_recv: Receive rate in 64 * bytes per second
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* @tx_x_calc: Calculated rate in bytes per second
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* @tx_rtt: Estimate of current round trip time in usecs
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* @tx_p: Current loss event rate (0-1) scaled by 1000000
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* @tx_s: Packet size in bytes
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* @tx_t_rto: Nofeedback Timer setting in usecs
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* @tx_t_ipi: Interpacket (send) interval (RFC 3448, 4.6) in usecs
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* @tx_state: Sender state, one of %ccid3_hc_tx_states
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* @tx_last_win_count: Last window counter sent
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* @tx_t_last_win_count: Timestamp of earliest packet
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* with last_win_count value sent
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* @tx_no_feedback_timer: Handle to no feedback timer
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* @tx_t_ld: Time last doubled during slow start
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* @tx_t_nom: Nominal send time of next packet
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* @tx_delta: Send timer delta (RFC 3448, 4.6) in usecs
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* @tx_hist: Packet history
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* @tx_options_received: Parsed set of retrieved options
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*/
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struct ccid3_hc_tx_sock {
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u64 tx_x;
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u64 tx_x_recv;
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u32 tx_x_calc;
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u32 tx_rtt;
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u32 tx_p;
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u32 tx_t_rto;
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u32 tx_t_ipi;
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u16 tx_s;
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enum ccid3_hc_tx_states tx_state:8;
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u8 tx_last_win_count;
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ktime_t tx_t_last_win_count;
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struct timer_list tx_no_feedback_timer;
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ktime_t tx_t_ld;
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ktime_t tx_t_nom;
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u32 tx_delta;
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struct tfrc_tx_hist_entry *tx_hist;
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struct ccid3_options_received tx_options_received;
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};
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static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
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{
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struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
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BUG_ON(hctx == NULL);
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return hctx;
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}
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/* TFRC receiver states */
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enum ccid3_hc_rx_states {
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TFRC_RSTATE_NO_DATA = 1,
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TFRC_RSTATE_DATA,
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TFRC_RSTATE_TERM = 127,
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};
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/**
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* struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
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* @rx_last_counter: Tracks window counter (RFC 4342, 8.1)
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* @rx_state: Receiver state, one of %ccid3_hc_rx_states
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* @rx_bytes_recv: Total sum of DCCP payload bytes
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* @rx_x_recv: Receiver estimate of send rate (RFC 3448, sec. 4.3)
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* @rx_rtt: Receiver estimate of RTT
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* @rx_tstamp_last_feedback: Time at which last feedback was sent
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* @rx_hist: Packet history (loss detection + RTT sampling)
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* @rx_li_hist: Loss Interval database
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* @rx_s: Received packet size in bytes
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* @rx_pinv: Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
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*/
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struct ccid3_hc_rx_sock {
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u8 rx_last_counter:4;
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enum ccid3_hc_rx_states rx_state:8;
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u32 rx_bytes_recv;
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u32 rx_x_recv;
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u32 rx_rtt;
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ktime_t rx_tstamp_last_feedback;
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struct tfrc_rx_hist rx_hist;
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struct tfrc_loss_hist rx_li_hist;
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u16 rx_s;
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#define rx_pinv rx_li_hist.i_mean
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};
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static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
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{
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struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
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BUG_ON(hcrx == NULL);
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return hcrx;
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}
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#endif /* _DCCP_CCID3_H_ */
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