#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/config.h>#include <linux/compiler.h>#include <linux/list.h>#include <linux/time.h>#include <linux/types.h> /* Read about the ECN nonce to see why it is 253 */#define DCCP_MAX_ACKVEC_LEN 253 #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 the DCCP draft * Appendix A. * * @dccpav_buf_head - circular buffer head * @dccpav_buf_tail - circular buffer tail * @dccpav_buf_ackno - ack # of the most recent packet acknowledgeable in the * 		       buffer (i.e. %dccpav_buf_head) * @dccpav_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: * * @dccpav_ack_ptr - the value of buf_head at the time of acknowledgement. * @dccpav_records - list of dccp_ackvec_record * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0. * * @dccpav_time		- the time in usecs * @dccpav_buf - circular buffer of acknowledgeable packets */struct dccp_ackvec {	u64		dccpav_buf_ackno;	struct list_head dccpav_records;	struct timeval	dccpav_time;	u8		dccpav_buf_head;	u8		dccpav_buf_tail;	u8		dccpav_ack_ptr;	u8		dccpav_sent_len;	u8		dccpav_vec_len;	u8		dccpav_buf_nonce;	u8		dccpav_ack_nonce;	u8		dccpav_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 dccpavr_ack_seqno * * @dccpavr_node - node in dccpav_records * @dccpavr_ack_seqno - sequence number of the packet this record was sent on * @dccpavr_ack_ackno - sequence number being acknowledged * @dccpavr_ack_ptr - pointer into dccpav_buf where this record starts * @dccpavr_ack_nonce - dccpav_ack_nonce at the time this record was sent * @dccpavr_sent_len - lenght of the record in dccpav_buf */struct dccp_ackvec_record {	struct list_head dccpavr_node;	u64		 dccpavr_ack_seqno;	u64		 dccpavr_ack_ackno;	u8		 dccpavr_ack_ptr;	u8		 dccpavr_ack_nonce;	u8		 dccpavr_sent_len;}; struct sock;struct sk_buff; #ifdef CONFIG_IP_DCCP_ACKVECextern 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,			     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->dccpav_sent_len != av->dccpav_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 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 */