[deliverable/linux.git] / net / dccp / ccids / ccid2.h

/*
 *  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_ */
Commit	Line	Data
2a91aa39	1	/*
2a91aa39 AB	2	* Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	17	*/
	18	#ifndef _DCCP_CCID2_H_
	19	#define _DCCP_CCID2_H_
	20
91f0ebf7 ACM	21	#include <linux/timer.h>
	22	#include <linux/types.h>
	23	#include "../ccid.h"
d82b6f85 GR	24	#include "../dccp.h"
	25
	26	/*
	27	* CCID-2 timestamping faces the same issues as TCP timestamping.
	28	* Hence we reuse/share as much of the code as possible.
	29	*/
	30	#define ccid2_time_stamp tcp_time_stamp
	31
63df18ad GR	32	/* NUMDUPACK parameter from RFC 4341, p. 6 */
63df18ad GR	33	#define NUMDUPACK 3
91f0ebf7	34
2a91aa39 AB	35	struct ccid2_seq {
2a91aa39 AB	36	u64 ccid2s_seq;
d82b6f85	37	u32 ccid2s_sent;
2a91aa39 AB	38	int ccid2s_acked;
	39	struct ccid2_seq *ccid2s_prev;
	40	struct ccid2_seq *ccid2s_next;
	41	};
	42
6472c051	43	#define CCID2_SEQBUF_LEN 1024
07978aab AB	44	#define CCID2_SEQBUF_MAX 128
07978aab AB	45
d346d886 SJ	46	/*
	47	* Multiple of congestion window to keep the sequence window at
	48	* (RFC 4340 7.5.2)
	49	*/
	50	#define CCID2_WIN_CHANGE_FACTOR 5
	51
aa1b1ff0 GR	52	/**
aa1b1ff0 GR	53	* struct ccid2_hc_tx_sock - CCID2 TX half connection
b1c00fe3 GR	54	* @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5
b1c00fe3 GR	55	* @tx_packets_acked: Ack counter for deriving cwnd growth (RFC 3465)
231cc2aa GR	56	* @tx_srtt: smoothed RTT estimate, scaled by 2^3
	57	* @tx_mdev: smoothed RTT variation, scaled by 2^2
	58	* @tx_mdev_max: maximum of @mdev during one flight
	59	* @tx_rttvar: moving average/maximum of @mdev_max
	60	* @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988)
	61	* @tx_rtt_seq: to decay RTTVAR at most once per flight
113ced1f GR	62	* @tx_cwnd_used: actually used cwnd, W_used of RFC 2861
	63	* @tx_expected_wnd: moving average of @tx_cwnd_used
	64	* @tx_cwnd_stamp: to track idle periods in CWV
	65	* @tx_lsndtime: last time (in jiffies) a data packet was sent
b1c00fe3 GR	66	* @tx_rpseq: last consecutive seqno
b1c00fe3 GR	67	* @tx_rpdupack: dupacks since rpseq
7e87fe84	68	* @tx_av_chunks: list of Ack Vectors received on current skb
aa1b1ff0	69	*/
2a91aa39	70	struct ccid2_hc_tx_sock {
b1c00fe3 GR	71	u32 tx_cwnd;
	72	u32 tx_ssthresh;
	73	u32 tx_pipe;
	74	u32 tx_packets_acked;
	75	struct ccid2_seq *tx_seqbuf[CCID2_SEQBUF_MAX];
	76	int tx_seqbufc;
	77	struct ccid2_seq *tx_seqh;
	78	struct ccid2_seq *tx_seqt;
231cc2aa GR	79
	80	/* RTT measurement: variables/principles are the same as in TCP */
	81	u32 tx_srtt,
	82	tx_mdev,
	83	tx_mdev_max,
	84	tx_rttvar,
	85	tx_rto;
	86	u64 tx_rtt_seq:48;
b1c00fe3	87	struct timer_list tx_rtotimer;
231cc2aa	88
113ced1f GR	89	/* Congestion Window validation (optional, RFC 2861) */
	90	u32 tx_cwnd_used,
	91	tx_expected_wnd,
	92	tx_cwnd_stamp,
	93	tx_lsndtime;
	94
b1c00fe3 GR	95	u64 tx_rpseq;
b1c00fe3 GR	96	int tx_rpdupack;
d82b6f85	97	u32 tx_last_cong;
b1c00fe3	98	u64 tx_high_ack;
7e87fe84	99	struct list_head tx_av_chunks;
2a91aa39 AB	100	};
2a91aa39 AB	101
1c0e0a05 GR	102	static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc)
	103	{
	104	return hc->tx_pipe >= hc->tx_cwnd;
	105	}
	106
b4d5f4b2 GR	107	/*
	108	* Convert RFC 3390 larger initial window into an equivalent number of packets.
	109	* This is based on the numbers specified in RFC 5681, 3.1.
	110	*/
	111	static inline u32 rfc3390_bytes_to_packets(const u32 smss)
	112	{
	113	return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3);
	114	}
	115
58fdea0f GR	116	/**
	117	* struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection
	118	* @rx_num_data_pkts: number of data packets received since last feedback
	119	*/
2a91aa39	120	struct ccid2_hc_rx_sock {
58fdea0f	121	u32 rx_num_data_pkts;
2a91aa39 AB	122	};
2a91aa39 AB	123
91f0ebf7 ACM	124	static inline struct ccid2_hc_tx_sock ccid2_hc_tx_sk(const struct sock sk)
	125	{
	126	return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
	127	}
	128
	129	static inline struct ccid2_hc_rx_sock ccid2_hc_rx_sk(const struct sock sk)
	130	{
	131	return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
	132	}
2a91aa39	133	#endif /* _DCCP_CCID2_H_ */