#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 */