/*
* Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _DCCP_CCID2_H_
#define _DCCP_CCID2_H_
#include <linux/timer.h>
#include <linux/types.h>
#include "../ccid.h"
#include "../dccp.h"
/*
* CCID-2 timestamping faces the same issues as TCP timestamping.
* Hence we reuse/share as much of the code as possible.
*/
#define ccid2_time_stamp tcp_time_stamp
/* NUMDUPACK parameter from RFC 4341, p. 6 */
#define NUMDUPACK 3
struct ccid2_seq {
u64 ccid2s_seq;
u32 ccid2s_sent;
int ccid2s_acked;
struct ccid2_seq *ccid2s_prev;
struct ccid2_seq *ccid2s_next;
};
#define CCID2_SEQBUF_LEN 1024
#define CCID2_SEQBUF_MAX 128
/*
* Multiple of congestion window to keep the sequence window at
* (RFC 4340 7.5.2)
*/
#define CCID2_WIN_CHANGE_FACTOR 5
/**
* struct ccid2_hc_tx_sock - CCID2 TX half connection
* @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5
* @tx_packets_acked: Ack counter for deriving cwnd growth (RFC 3465)
* @tx_srtt: smoothed RTT estimate, scaled by 2^3
* @tx_mdev: smoothed RTT variation, scaled by 2^2
* @tx_mdev_max: maximum of @mdev during one flight
* @tx_rttvar: moving average/maximum of @mdev_max
* @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988)
* @tx_rtt_seq: to decay RTTVAR at most once per flight
* @tx_cwnd_used: actually used cwnd, W_used of RFC 2861
* @tx_expected_wnd: moving average of @tx_cwnd_used
* @tx_cwnd_stamp: to track idle periods in CWV
* @tx_lsndtime: last time (in jiffies) a data packet was sent
* @tx_rpseq: last consecutive seqno
* @tx_rpdupack: dupacks since rpseq
* @tx_av_chunks: list of Ack Vectors received on current skb
*/
struct ccid2_hc_tx_sock {
u32 tx_cwnd;
u32 tx_ssthresh;
u32 tx_pipe;
u32 tx_packets_acked;
struct ccid2_seq *tx_seqbuf[CCID2_SEQBUF_MAX];
int tx_seqbufc;
struct ccid2_seq *tx_seqh;
struct ccid2_seq *tx_seqt;
/* RTT measurement: variables/principles are the same as in TCP */
u32 tx_srtt,
tx_mdev,
tx_mdev_max,
tx_rttvar,
tx_rto;
u64 tx_rtt_seq:48;
struct timer_list tx_rtotimer;
/* Congestion Window validation (optional, RFC 2861) */
u32 tx_cwnd_used,
tx_expected_wnd,
tx_cwnd_stamp,
tx_lsndtime;
u64 tx_rpseq;
int tx_rpdupack;
u32 tx_last_cong;
u64 tx_high_ack;
struct list_head tx_av_chunks;
};
static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc)
{
return hc->tx_pipe >= hc->tx_cwnd;
}
/*
* Convert RFC 3390 larger initial window into an equivalent number of packets.
* This is based on the numbers specified in RFC 5681, 3.1.
*/
static inline u32 rfc3390_bytes_to_packets(const u32 smss)
{
return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3);
}
/**
* struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection
* @rx_num_data_pkts: number of data packets received since last feedback
*/
struct ccid2_hc_rx_sock {
u32 rx_num_data_pkts;
};
static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk)
{
return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
}
static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk)
{
return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
}
#endif /* _DCCP_CCID2_H_ */
