[linux.git] / net / dccp / ackvec.h

#ifndef _ACKVEC_H
#define _ACKVEC_H
/*
 *  net/dccp/ackvec.h
 *
 *  An implementation of the DCCP protocol
 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <[email protected]>
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License version 2 as
 *	published by the Free Software Foundation.
 */

#include <linux/dccp.h>
#include <linux/compiler.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/types.h>

/* We can spread an ack vector across multiple options */
#define DCCP_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * 2)

/* Estimated minimum average Ack Vector length - used for updating MPS */
#define DCCPAV_MIN_OPTLEN	16

#define DCCP_ACKVEC_STATE_RECEIVED	0
#define DCCP_ACKVEC_STATE_ECN_MARKED	(1 << 6)
#define DCCP_ACKVEC_STATE_NOT_RECEIVED	(3 << 6)

#define DCCP_ACKVEC_STATE_MASK		0xC0 /* 11000000 */
#define DCCP_ACKVEC_LEN_MASK		0x3F /* 00111111 */

/** struct dccp_ackvec - ack vector
 *
 * This data structure is the one defined in RFC 4340, Appendix A.
 *
 * @av_buf_head - circular buffer head
 * @av_buf_tail - circular buffer tail
 * @av_buf_ackno - ack # of the most recent packet acknowledgeable in the
 *		       buffer (i.e. %av_buf_head)
 * @av_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
 * 		       by the buffer with State 0
 *
 * Additionally, the HC-Receiver must keep some information about the
 * Ack Vectors it has recently sent. For each packet sent carrying an
 * Ack Vector, it remembers four variables:
 *
 * @av_records - list of dccp_ackvec_record
 * @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
 *
 * @av_time - the time in usecs
 * @av_buf - circular buffer of acknowledgeable packets
 */
struct dccp_ackvec {
	u64			av_buf_ackno;
	struct list_head	av_records;
	ktime_t			av_time;
	u16			av_buf_head;
	u16			av_vec_len;
	u8			av_buf_nonce;
	u8			av_ack_nonce;
	u8			av_buf[DCCP_MAX_ACKVEC_LEN];
};

/** struct dccp_ackvec_record - ack vector record
 *
 * ACK vector record as defined in Appendix A of spec.
 *
 * The list is sorted by avr_ack_seqno
 *
 * @avr_node - node in av_records
 * @avr_ack_seqno - sequence number of the packet this record was sent on
 * @avr_ack_ackno - sequence number being acknowledged
 * @avr_ack_ptr - pointer into av_buf where this record starts
 * @avr_ack_nonce - av_ack_nonce at the time this record was sent
 * @avr_sent_len - lenght of the record in av_buf
 */
struct dccp_ackvec_record {
	struct list_head avr_node;
	u64		 avr_ack_seqno;
	u64		 avr_ack_ackno;
	u16		 avr_ack_ptr;
	u16		 avr_sent_len;
	u8		 avr_ack_nonce;
};

struct sock;
struct sk_buff;

extern int dccp_ackvec_init(void);
extern void dccp_ackvec_exit(void);

extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
extern void dccp_ackvec_free(struct dccp_ackvec *av);

extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
			   const u64 ackno, const u8 state);

extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
					struct sock *sk, const u64 ackno);
extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
			     u64 *ackno, const u8 opt,
			     const u8 *value, const u8 len);

extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);

static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
{
	return av->av_vec_len;
}
#endif /* _ACKVEC_H */
Commit	Line	Data
ae31c339 ACM	1	#ifndef _ACKVEC_H
	2	#define _ACKVEC_H
	3	/*
	4	* net/dccp/ackvec.h
	5	*
	6	* An implementation of the DCCP protocol
	7	* Copyright (c) 2005 Arnaldo Carvalho de Melo <[email protected]>
	8	*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
b20a9c24	14	#include <linux/dccp.h>
ae31c339	15	#include <linux/compiler.h>
b8bda9d7	16	#include <linux/ktime.h>
02bcf28c	17	#include <linux/list.h>
ae31c339 ACM	18	#include <linux/types.h>
ae31c339 ACM	19
bdf13d20	20	/* We can spread an ack vector across multiple options */
b20a9c24	21	#define DCCP_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * 2)
ae31c339	22
361a5c1d GR	23	/* Estimated minimum average Ack Vector length - used for updating MPS */
	24	#define DCCPAV_MIN_OPTLEN 16
	25
ae31c339 ACM	26	#define DCCP_ACKVEC_STATE_RECEIVED 0
	27	#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6)
	28	#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6)
	29
	30	#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */
	31	#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */
	32
	33	/** struct dccp_ackvec - ack vector
	34	*
0e64e94e	35	* This data structure is the one defined in RFC 4340, Appendix A.
ae31c339	36	*
a47c5104 GR	37	* @av_buf_head - circular buffer head
	38	* @av_buf_tail - circular buffer tail
	39	* @av_buf_ackno - ack # of the most recent packet acknowledgeable in the
	40	* buffer (i.e. %av_buf_head)
	41	* @av_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
ae31c339 ACM	42	* by the buffer with State 0
	43	*
	44	* Additionally, the HC-Receiver must keep some information about the
	45	* Ack Vectors it has recently sent. For each packet sent carrying an
	46	* Ack Vector, it remembers four variables:
	47	*
a47c5104 GR	48	* @av_records - list of dccp_ackvec_record
a47c5104 GR	49	* @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
ae31c339	50	*
a47c5104 GR	51	* @av_time - the time in usecs
a47c5104 GR	52	* @av_buf - circular buffer of acknowledgeable packets
ae31c339 ACM	53	*/
ae31c339 ACM	54	struct dccp_ackvec {
a47c5104 GR	55	u64 av_buf_ackno;
	56	struct list_head av_records;
	57	ktime_t av_time;
	58	u16 av_buf_head;
	59	u16 av_vec_len;
	60	u8 av_buf_nonce;
	61	u8 av_ack_nonce;
	62	u8 av_buf[DCCP_MAX_ACKVEC_LEN];
ae31c339 ACM	63	};
ae31c339 ACM	64
02bcf28c AB	65	/** struct dccp_ackvec_record - ack vector record
	66	*
	67	* ACK vector record as defined in Appendix A of spec.
	68	*
a47c5104	69	* The list is sorted by avr_ack_seqno
02bcf28c	70	*
a47c5104 GR	71	* @avr_node - node in av_records
	72	* @avr_ack_seqno - sequence number of the packet this record was sent on
	73	* @avr_ack_ackno - sequence number being acknowledged
	74	* @avr_ack_ptr - pointer into av_buf where this record starts
	75	* @avr_ack_nonce - av_ack_nonce at the time this record was sent
	76	* @avr_sent_len - lenght of the record in av_buf
02bcf28c AB	77	*/
02bcf28c AB	78	struct dccp_ackvec_record {
a47c5104 GR	79	struct list_head avr_node;
	80	u64 avr_ack_seqno;
	81	u64 avr_ack_ackno;
	82	u16 avr_ack_ptr;
	83	u16 avr_sent_len;
	84	u8 avr_ack_nonce;
02bcf28c AB	85	};
02bcf28c AB	86
ae31c339 ACM	87	struct sock;
	88	struct sk_buff;
	89
9b07ef5d ACM	90	extern int dccp_ackvec_init(void);
	91	extern void dccp_ackvec_exit(void);
	92
7400d781	93	extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
ae31c339 ACM	94	extern void dccp_ackvec_free(struct dccp_ackvec *av);
	95
	96	extern int dccp_ackvec_add(struct dccp_ackvec av, const struct sock sk,
	97	const u64 ackno, const u8 state);
	98
	99	extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
	100	struct sock *sk, const u64 ackno);
	101	extern int dccp_ackvec_parse(struct sock sk, const struct sk_buff skb,
bdf13d20 AB	102	u64 *ackno, const u8 opt,
bdf13d20 AB	103	const u8 *value, const u8 len);
ae31c339 ACM	104
	105	extern int dccp_insert_option_ackvec(struct sock sk, struct sk_buff skb);
	106
	107	static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
	108	{
a47c5104	109	return av->av_vec_len;
ae31c339	110	}
ae31c339	111	#endif /* _ACKVEC_H */