134 lines
3.8 KiB
C
134 lines
3.8 KiB
C
#ifndef _ACKVEC_H
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#define _ACKVEC_H
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/*
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* net/dccp/ackvec.h
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*
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* An implementation of the DCCP protocol
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* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@mandriva.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/config.h>
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#include <linux/compiler.h>
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#include <linux/time.h>
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#include <linux/types.h>
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/* Read about the ECN nonce to see why it is 253 */
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#define DCCP_MAX_ACKVEC_LEN 253
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#define DCCP_ACKVEC_STATE_RECEIVED 0
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#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6)
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#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6)
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#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */
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#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */
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/** struct dccp_ackvec - ack vector
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*
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* This data structure is the one defined in the DCCP draft
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* Appendix A.
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*
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* @dccpav_buf_head - circular buffer head
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* @dccpav_buf_tail - circular buffer tail
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* @dccpav_buf_ackno - ack # of the most recent packet acknowledgeable in the
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* buffer (i.e. %dccpav_buf_head)
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* @dccpav_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
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* by the buffer with State 0
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*
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* Additionally, the HC-Receiver must keep some information about the
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* Ack Vectors it has recently sent. For each packet sent carrying an
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* Ack Vector, it remembers four variables:
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*
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* @dccpav_ack_seqno - the Sequence Number used for the packet
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* (HC-Receiver seqno)
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* @dccpav_ack_ptr - the value of buf_head at the time of acknowledgement.
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* @dccpav_ack_ackno - the Acknowledgement Number used for the packet
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* (HC-Sender seqno)
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* @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
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*
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* @dccpav_buf_len - circular buffer length
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* @dccpav_time - the time in usecs
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* @dccpav_buf - circular buffer of acknowledgeable packets
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*/
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struct dccp_ackvec {
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u64 dccpav_buf_ackno;
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u64 dccpav_ack_seqno;
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u64 dccpav_ack_ackno;
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struct timeval dccpav_time;
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u8 dccpav_buf_head;
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u8 dccpav_buf_tail;
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u8 dccpav_ack_ptr;
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u8 dccpav_sent_len;
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u8 dccpav_vec_len;
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u8 dccpav_buf_len;
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u8 dccpav_buf_nonce;
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u8 dccpav_ack_nonce;
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u8 dccpav_buf[0];
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};
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struct sock;
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struct sk_buff;
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#ifdef CONFIG_IP_DCCP_ACKVEC
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extern struct dccp_ackvec *dccp_ackvec_alloc(unsigned int len,
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const gfp_t priority);
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extern void dccp_ackvec_free(struct dccp_ackvec *av);
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extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
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const u64 ackno, const u8 state);
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extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
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struct sock *sk, const u64 ackno);
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extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
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const u8 opt, const u8 *value, const u8 len);
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extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);
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static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
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{
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return av->dccpav_sent_len != av->dccpav_vec_len;
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}
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#else /* CONFIG_IP_DCCP_ACKVEC */
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static inline struct dccp_ackvec *dccp_ackvec_alloc(unsigned int len,
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const gfp_t priority)
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{
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return NULL;
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}
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static inline void dccp_ackvec_free(struct dccp_ackvec *av)
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{
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}
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static inline int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
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const u64 ackno, const u8 state)
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{
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return -1;
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}
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static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
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struct sock *sk, const u64 ackno)
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{
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}
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static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
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const u8 opt, const u8 *value, const u8 len)
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{
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return -1;
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}
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static inline int dccp_insert_option_ackvec(const struct sock *sk,
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const struct sk_buff *skb)
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{
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return -1;
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}
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static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
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{
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return 0;
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}
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#endif /* CONFIG_IP_DCCP_ACKVEC */
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#endif /* _ACKVEC_H */
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