[linux-2.6-block.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 <acme@mandriva.com>
 *
 *	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/compiler.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/types.h>

/* Read about the ECN nonce to see why it is 253 */
#define DCCP_MAX_ACKVEC_OPT_LEN 253
/* We can spread an ack vector across multiple options */
#define DCCP_MAX_ACKVEC_LEN (DCCP_MAX_ACKVEC_OPT_LEN * 2)

#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;

#ifdef CONFIG_IP_DCCP_ACKVEC
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;
}
#else /* CONFIG_IP_DCCP_ACKVEC */
static inline int dccp_ackvec_init(void)
{
	return 0;
}

static inline void dccp_ackvec_exit(void)
{
}

static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
{
	return NULL;
}

static inline void dccp_ackvec_free(struct dccp_ackvec *av)
{
}

static inline int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
				  const u64 ackno, const u8 state)
{
	return -1;
}

static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
					       struct sock *sk, const u64 ackno)
{
}

static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
				    const u64 *ackno, const u8 opt,
				    const u8 *value, const u8 len)
{
	return -1;
}

static inline int dccp_insert_option_ackvec(const struct sock *sk,
					    const struct sk_buff *skb)
{
	return -1;
}

static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
{
	return 0;
}
#endif /* CONFIG_IP_DCCP_ACKVEC */
#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 <acme@mandriva.com>
	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
ae31c339	14	#include <linux/compiler.h>
b8bda9d7	15	#include <linux/ktime.h>
02bcf28c	16	#include <linux/list.h>
ae31c339 ACM	17	#include <linux/types.h>
	18
	19	/* Read about the ECN nonce to see why it is 253 */
bdf13d20 AB	20	#define DCCP_MAX_ACKVEC_OPT_LEN 253
	21	/* We can spread an ack vector across multiple options */
	22	#define DCCP_MAX_ACKVEC_LEN (DCCP_MAX_ACKVEC_OPT_LEN * 2)
ae31c339 ACM	23
	24	#define DCCP_ACKVEC_STATE_RECEIVED 0
	25	#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6)
	26	#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6)
	27
	28	#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */
	29	#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */
	30
	31	/** struct dccp_ackvec - ack vector
	32	*
0e64e94e	33	* This data structure is the one defined in RFC 4340, Appendix A.
ae31c339	34	*
a47c5104 GR	35	* @av_buf_head - circular buffer head
	36	* @av_buf_tail - circular buffer tail
	37	* @av_buf_ackno - ack # of the most recent packet acknowledgeable in the
	38	* buffer (i.e. %av_buf_head)
	39	* @av_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
ae31c339 ACM	40	* by the buffer with State 0
	41	*
	42	* Additionally, the HC-Receiver must keep some information about the
	43	* Ack Vectors it has recently sent. For each packet sent carrying an
	44	* Ack Vector, it remembers four variables:
	45	*
a47c5104 GR	46	* @av_records - list of dccp_ackvec_record
a47c5104 GR	47	* @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
ae31c339	48	*
a47c5104 GR	49	* @av_time - the time in usecs
a47c5104 GR	50	* @av_buf - circular buffer of acknowledgeable packets
ae31c339 ACM	51	*/
ae31c339 ACM	52	struct dccp_ackvec {
a47c5104 GR	53	u64 av_buf_ackno;
	54	struct list_head av_records;
	55	ktime_t av_time;
	56	u16 av_buf_head;
	57	u16 av_vec_len;
	58	u8 av_buf_nonce;
	59	u8 av_ack_nonce;
	60	u8 av_buf[DCCP_MAX_ACKVEC_LEN];
ae31c339 ACM	61	};
ae31c339 ACM	62
02bcf28c AB	63	/** struct dccp_ackvec_record - ack vector record
	64	*
	65	* ACK vector record as defined in Appendix A of spec.
	66	*
a47c5104	67	* The list is sorted by avr_ack_seqno
02bcf28c	68	*
a47c5104 GR	69	* @avr_node - node in av_records
	70	* @avr_ack_seqno - sequence number of the packet this record was sent on
	71	* @avr_ack_ackno - sequence number being acknowledged
	72	* @avr_ack_ptr - pointer into av_buf where this record starts
	73	* @avr_ack_nonce - av_ack_nonce at the time this record was sent
	74	* @avr_sent_len - lenght of the record in av_buf
02bcf28c AB	75	*/
02bcf28c AB	76	struct dccp_ackvec_record {
a47c5104 GR	77	struct list_head avr_node;
	78	u64 avr_ack_seqno;
	79	u64 avr_ack_ackno;
	80	u16 avr_ack_ptr;
	81	u16 avr_sent_len;
	82	u8 avr_ack_nonce;
02bcf28c AB	83	};
02bcf28c AB	84
ae31c339 ACM	85	struct sock;
	86	struct sk_buff;
	87
	88	#ifdef CONFIG_IP_DCCP_ACKVEC
9b07ef5d ACM	89	extern int dccp_ackvec_init(void);
	90	extern void dccp_ackvec_exit(void);
	91
7400d781	92	extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
ae31c339 ACM	93	extern void dccp_ackvec_free(struct dccp_ackvec *av);
	94
	95	extern int dccp_ackvec_add(struct dccp_ackvec av, const struct sock sk,
	96	const u64 ackno, const u8 state);
	97
	98	extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
	99	struct sock *sk, const u64 ackno);
	100	extern int dccp_ackvec_parse(struct sock sk, const struct sk_buff skb,
bdf13d20 AB	101	u64 *ackno, const u8 opt,
bdf13d20 AB	102	const u8 *value, const u8 len);
ae31c339 ACM	103
	104	extern int dccp_insert_option_ackvec(struct sock sk, struct sk_buff skb);
	105
	106	static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
	107	{
a47c5104	108	return av->av_vec_len;
ae31c339 ACM	109	}
ae31c339 ACM	110	#else /* CONFIG_IP_DCCP_ACKVEC */
9b07ef5d ACM	111	static inline int dccp_ackvec_init(void)
	112	{
	113	return 0;
	114	}
	115
	116	static inline void dccp_ackvec_exit(void)
	117	{
	118	}
	119
7400d781	120	static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
ae31c339 ACM	121	{
	122	return NULL;
	123	}
	124
	125	static inline void dccp_ackvec_free(struct dccp_ackvec *av)
	126	{
	127	}
	128
	129	static inline int dccp_ackvec_add(struct dccp_ackvec av, const struct sock sk,
	130	const u64 ackno, const u8 state)
	131	{
	132	return -1;
	133	}
	134
	135	static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
	136	struct sock *sk, const u64 ackno)
	137	{
	138	}
	139
	140	static inline int dccp_ackvec_parse(struct sock sk, const struct sk_buff skb,
bdf13d20 AB	141	const u64 *ackno, const u8 opt,
bdf13d20 AB	142	const u8 *value, const u8 len)
ae31c339 ACM	143	{
	144	return -1;
	145	}
	146
	147	static inline int dccp_insert_option_ackvec(const struct sock *sk,
	148	const struct sk_buff *skb)
	149	{
	150	return -1;
	151	}
	152
	153	static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
	154	{
	155	return 0;
	156	}
	157	#endif /* CONFIG_IP_DCCP_ACKVEC */
	158	#endif /* _ACKVEC_H */