a402a5aa9b
There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
139 lines
4.7 KiB
C
139 lines
4.7 KiB
C
#ifndef _ACKVEC_H
|
|
#define _ACKVEC_H
|
|
/*
|
|
* net/dccp/ackvec.h
|
|
*
|
|
* An implementation of Ack Vectors for the DCCP protocol
|
|
* Copyright (c) 2007 University of Aberdeen, Scotland, UK
|
|
* 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/dccp.h>
|
|
#include <linux/compiler.h>
|
|
#include <linux/list.h>
|
|
#include <linux/types.h>
|
|
|
|
/*
|
|
* Ack Vector buffer space is static, in multiples of %DCCP_SINGLE_OPT_MAXLEN,
|
|
* the maximum size of a single Ack Vector. Setting %DCCPAV_NUM_ACKVECS to 1
|
|
* will be sufficient for most cases of low Ack Ratios, using a value of 2 gives
|
|
* more headroom if Ack Ratio is higher or when the sender acknowledges slowly.
|
|
* The maximum value is bounded by the u16 types for indices and functions.
|
|
*/
|
|
#define DCCPAV_NUM_ACKVECS 2
|
|
#define DCCPAV_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS)
|
|
|
|
/* Estimated minimum average Ack Vector length - used for updating MPS */
|
|
#define DCCPAV_MIN_OPTLEN 16
|
|
|
|
/* Threshold for coping with large bursts of losses */
|
|
#define DCCPAV_BURST_THRESH (DCCPAV_MAX_ACKVEC_LEN / 8)
|
|
|
|
enum dccp_ackvec_states {
|
|
DCCPAV_RECEIVED = 0x00,
|
|
DCCPAV_ECN_MARKED = 0x40,
|
|
DCCPAV_RESERVED = 0x80,
|
|
DCCPAV_NOT_RECEIVED = 0xC0
|
|
};
|
|
#define DCCPAV_MAX_RUNLEN 0x3F
|
|
|
|
static inline u8 dccp_ackvec_runlen(const u8 *cell)
|
|
{
|
|
return *cell & DCCPAV_MAX_RUNLEN;
|
|
}
|
|
|
|
static inline u8 dccp_ackvec_state(const u8 *cell)
|
|
{
|
|
return *cell & ~DCCPAV_MAX_RUNLEN;
|
|
}
|
|
|
|
/**
|
|
* struct dccp_ackvec - Ack Vector main data structure
|
|
*
|
|
* This implements a fixed-size circular buffer within an array and is largely
|
|
* based on Appendix A of RFC 4340.
|
|
*
|
|
* @av_buf: circular buffer storage area
|
|
* @av_buf_head: head index; begin of live portion in @av_buf
|
|
* @av_buf_tail: tail index; first index _after_ the live portion in @av_buf
|
|
* @av_buf_ackno: highest seqno of acknowledgeable packet recorded in @av_buf
|
|
* @av_tail_ackno: lowest seqno of acknowledgeable packet recorded in @av_buf
|
|
* @av_buf_nonce: ECN nonce sums, each covering subsequent segments of up to
|
|
* %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf
|
|
* @av_overflow: if 1 then buf_head == buf_tail indicates buffer wraparound
|
|
* @av_records: list of %dccp_ackvec_record (Ack Vectors sent previously)
|
|
*/
|
|
struct dccp_ackvec {
|
|
u8 av_buf[DCCPAV_MAX_ACKVEC_LEN];
|
|
u16 av_buf_head;
|
|
u16 av_buf_tail;
|
|
u64 av_buf_ackno:48;
|
|
u64 av_tail_ackno:48;
|
|
bool av_buf_nonce[DCCPAV_NUM_ACKVECS];
|
|
u8 av_overflow:1;
|
|
struct list_head av_records;
|
|
};
|
|
|
|
/**
|
|
* struct dccp_ackvec_record - Records information about sent Ack Vectors
|
|
*
|
|
* These list entries define the additional information which the HC-Receiver
|
|
* keeps about recently-sent Ack Vectors; again refer to RFC 4340, Appendix A.
|
|
*
|
|
* @avr_node: the list node in @av_records
|
|
* @avr_ack_seqno: sequence number of the packet the Ack Vector was sent on
|
|
* @avr_ack_ackno: the Ack number that this record/Ack Vector refers to
|
|
* @avr_ack_ptr: pointer into @av_buf where this record starts
|
|
* @avr_ack_runlen: run length of @avr_ack_ptr at the time of sending
|
|
* @avr_ack_nonce: the sum of @av_buf_nonce's at the time this record was sent
|
|
*
|
|
* The list as a whole is sorted in descending order by @avr_ack_seqno.
|
|
*/
|
|
struct dccp_ackvec_record {
|
|
struct list_head avr_node;
|
|
u64 avr_ack_seqno:48;
|
|
u64 avr_ack_ackno:48;
|
|
u16 avr_ack_ptr;
|
|
u8 avr_ack_runlen;
|
|
u8 avr_ack_nonce:1;
|
|
};
|
|
|
|
int dccp_ackvec_init(void);
|
|
void dccp_ackvec_exit(void);
|
|
|
|
struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
|
|
void dccp_ackvec_free(struct dccp_ackvec *av);
|
|
|
|
void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb);
|
|
int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum);
|
|
void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno);
|
|
u16 dccp_ackvec_buflen(const struct dccp_ackvec *av);
|
|
|
|
static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av)
|
|
{
|
|
return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail;
|
|
}
|
|
|
|
/**
|
|
* struct dccp_ackvec_parsed - Record offsets of Ack Vectors in skb
|
|
* @vec: start of vector (offset into skb)
|
|
* @len: length of @vec
|
|
* @nonce: whether @vec had an ECN nonce of 0 or 1
|
|
* @node: FIFO - arranged in descending order of ack_ackno
|
|
*
|
|
* This structure is used by CCIDs to access Ack Vectors in a received skb.
|
|
*/
|
|
struct dccp_ackvec_parsed {
|
|
u8 *vec,
|
|
len,
|
|
nonce:1;
|
|
struct list_head node;
|
|
};
|
|
|
|
int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce);
|
|
void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks);
|
|
#endif /* _ACKVEC_H */
|