/* $Id: mcl_rlc.h,v 1.2 2003/10/27 09:55:48 roca Exp $ */
/*
 *  Copyright (c) 1999-2003 INRIA - Universite Paris 6 - All rights reserved
 *  (main authors: Julien Laboure - julien.laboure@inrialpes.fr
 *                 Vincent Roca - vincent.roca@inrialpes.fr)
 *
 *  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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 *  USA.
 */

/*
 * This file contains the headers for RLC congestion control module.
 */

#ifndef MCL_RLC_H  /* { */
#define MCL_RLC_H

#ifdef RLC /* { */

/*--- rlc_hdr_t Type ---*/
/* The RLC congestion control header block (32bits -> ALC compliant) */
typedef struct {
#ifdef  _BIT_FIELDS_LTOH
	u_char	rlc_reserved:7,	/* Unused, must be 0x55 (1010101) */
		rlc_sp:1;	/* Is this packet a Synchronisation Point (SP) ? */
#else
	u_char	rlc_sp:1,	/* Is this packet a Synchronisation Point (SP) ? */
	rlc_reserved:7;		/* Unused, must be 0x55 (1010101) */
#endif

	u_int8_t  rlc_layer; /* packet's layer (indice) */
	u_int16_t rlc_seqid; /* packet's Sequence number (per layer sequence) */
} rlc_hdr_t;


typedef struct late_list {
	struct late_list *next;	/* next late */
	u_int16_t	seq_num;/* RLC Sequence Number */
	int		ttw;	/* Time To Wait before considering lost */
} late_list_t;


typedef struct lost_list {
	struct lost_list *next;	/* next missing */
	int pkt_remaining; /* Number of packets to receive before we forget
				this one */
} lost_list_t;


typedef struct rlccb {
	int rlc_sp_cycle;	/* Interval between 2 SPs at layer 0 (in µsec)*/

	int rlc_pkt_timeout; 	/* Default Time To Wait for a late packet
				before assuming it's lost */

	int rlc_deaf_period;	/* Time for Deaf period after a dropped layer
				(in µsec) */

	int rlc_late_accepted;	/* if the amount of late packets between 2 SPs
				at top layer is <= rlc_late_accepted then a
				layer can be added */

	int rlc_loss_accepted;	/* if the amount of lost packets between 2 SPs
				at top layer is <= rlc_loss_accepted then
				a layer could be added */

	int rlc_loss_limit;	/* rlc_loss_limit / rlc_loss_timeout is the max
				loss rate for packet. */
	int rlc_loss_timeout;	/* if this rate is reached then we should drop
				the highest layer. */

	int rlc_lan_cc;		/* aggressive congestion ctrl setup for LAN tx*/
	
	/* For each layer, value of current sequence number */
	u_int16_t	tx_layers_seq[MAX_TX_LEVEL];

	/* For each layer, date for the next SP */
	u_int 		tx_next_sp[MAX_TX_LEVEL];

	/* For each layer, =1 if we are waiting for the first packet */
	char	 	rx_first_pkt[MAX_TX_LEVEL];

	/* For each layer, =1 if we are waiting for the first SP after deaf */
	char	 	rx_first_sp[MAX_TX_LEVEL];

	/* For each layer, seq number of the next packet to receive */
	u_int16_t 	rx_wait_for[MAX_TX_LEVEL];

	/* For each layer, list of missing seq number */
	late_list_t	rx_missing[MAX_TX_LEVEL];

	/* amount late packets since the last SP */
	u_int16_t	rx_nblate_since_sp;

	/* amount of recent late packets */
	u_int16_t	rx_nblate;

	/* amount lost packets since the last SP */
	u_int16_t	rx_nblost_since_sp;

	/* amount of recent lost packets */
	u_int16_t	rx_nblost;

	/* Current list of lost packets */
	lost_list_t	rx_lost;

	/* when in deaf period, specify the number of calls to 
	rlc_rx_timer remaining before end of deaf */	
	mcl_itime_t	rx_deaf_wait;

	/* remaining time_count till next call to rlc_rx_timer function */
	mcl_itime_t	rlc_rx_timer_count;

} rlccb_t;


/* For infos about all these CONSTANTS	*/
/* Refer to the descriptions of the	*/
/* corresponding rlccb member variables	*/
/*
 * Internet version
 */
#define RLC_SP_CYCLE		250000	 /* 0.25s, for fast layer addition */
#define RLC_DEAF_PERIOD		10000000 /* 10s, due to IGMP leave latency */
#define RLC_LATE_ACCEPTED	0
#define RLC_LOSS_ACCEPTED	0
#define RLC_PKT_TIMEOUT		500000
#define RLC_LOSS_LIMIT		1
#define RLC_LOSS_TIMEOUT	20

#define RLC_MAX_LATES		100
 
/*
 * Aggressive version
 *
 * This profile is more robust to packet losses and can be used
 * in situations where packet losses may be caused by something
 * else than congestion, or with multicast routing protocols that
 * can lead to an instable initial situation (e.g. with PIM-SM
 * while moving from the shared tree to the source specific tree).
 * Use with care...
 *
 * This mode can be set by changing the "rlc_aggr_cc" field in
 * file mcl_tx_prof.c.
 */
#define RLC_LAN_DEAF_PERIOD	1000000	/* small (1s) as a LAN reacts quickly */
#define RLC_LAN_LATE_ACCEPTED	1
#define RLC_LAN_LOSS_ACCEPTED	1
//#define RLC_LAN_LOSS_LIMIT	10	/* higher loss limit */
#define RLC_LAN_LOSS_LIMIT	2	/* higher loss limit */

#endif /* } RLC */

#endif /* }  MCL_RLC_H */