RPC/RDMA: adhere to protocol for unpadded client trailing write chunks.
[linux-2.6-block.git] / net / dccp / ackvec.h
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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>
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17#include <linux/types.h>
18
19/* Read about the ECN nonce to see why it is 253 */
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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)
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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 *
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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
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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 *
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46 * @av_records - list of dccp_ackvec_record
47 * @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
ae31c339 48 *
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49 * @av_time - the time in usecs
50 * @av_buf - circular buffer of acknowledgeable packets
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51 */
52struct dccp_ackvec {
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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];
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61};
62
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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 *
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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
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75 */
76struct dccp_ackvec_record {
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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;
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83};
84
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85struct sock;
86struct sk_buff;
87
88#ifdef CONFIG_IP_DCCP_ACKVEC
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89extern int dccp_ackvec_init(void);
90extern void dccp_ackvec_exit(void);
91
7400d781 92extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
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93extern void dccp_ackvec_free(struct dccp_ackvec *av);
94
95extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
96 const u64 ackno, const u8 state);
97
98extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
99 struct sock *sk, const u64 ackno);
100extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
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101 u64 *ackno, const u8 opt,
102 const u8 *value, const u8 len);
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103
104extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);
105
106static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
107{
a47c5104 108 return av->av_vec_len;
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109}
110#else /* CONFIG_IP_DCCP_ACKVEC */
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111static inline int dccp_ackvec_init(void)
112{
113 return 0;
114}
115
116static inline void dccp_ackvec_exit(void)
117{
118}
119
7400d781 120static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
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121{
122 return NULL;
123}
124
125static inline void dccp_ackvec_free(struct dccp_ackvec *av)
126{
127}
128
129static 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
135static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
136 struct sock *sk, const u64 ackno)
137{
138}
139
140static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
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141 const u64 *ackno, const u8 opt,
142 const u8 *value, const u8 len)
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143{
144 return -1;
145}
146
147static inline int dccp_insert_option_ackvec(const struct sock *sk,
148 const struct sk_buff *skb)
149{
150 return -1;
151}
152
153static 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 */