Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
14#include <linux/compiler.h>
15#include <linux/list.h>
16#include <linux/time.h>
17#include <linux/types.h>
18
19/* Read about the ECN nonce to see why it is 253 */
20#define DCCP_MAX_ACKVEC_LEN 253
21
22#define DCCP_ACKVEC_STATE_RECEIVED 0
23#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6)
24#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6)
25
26#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */
27#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */
28
29/** struct dccp_ackvec - ack vector
30 *
31 * This data structure is the one defined in the DCCP draft
32 * Appendix A.
33 *
34 * @dccpav_buf_head - circular buffer head
35 * @dccpav_buf_tail - circular buffer tail
36 * @dccpav_buf_ackno - ack # of the most recent packet acknowledgeable in the
37 * buffer (i.e. %dccpav_buf_head)
38 * @dccpav_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
39 * by the buffer with State 0
40 *
41 * Additionally, the HC-Receiver must keep some information about the
42 * Ack Vectors it has recently sent. For each packet sent carrying an
43 * Ack Vector, it remembers four variables:
44 *
45 * @dccpav_ack_ptr - the value of buf_head at the time of acknowledgement.
46 * @dccpav_records - list of dccp_ackvec_record
47 * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
48 *
49 * @dccpav_time - the time in usecs
50 * @dccpav_buf - circular buffer of acknowledgeable packets
51 */
52struct dccp_ackvec {
53 u64 dccpav_buf_ackno;
54 struct list_head dccpav_records;
55 struct timeval dccpav_time;
56 u8 dccpav_buf_head;
57 u8 dccpav_buf_tail;
58 u8 dccpav_ack_ptr;
59 u8 dccpav_sent_len;
60 u8 dccpav_vec_len;
61 u8 dccpav_buf_nonce;
62 u8 dccpav_ack_nonce;
63 u8 dccpav_buf[DCCP_MAX_ACKVEC_LEN];
64};
65
66/** struct dccp_ackvec_record - ack vector record
67 *
68 * ACK vector record as defined in Appendix A of spec.
69 *
70 * The list is sorted by dccpavr_ack_seqno
71 *
72 * @dccpavr_node - node in dccpav_records
73 * @dccpavr_ack_seqno - sequence number of the packet this record was sent on
74 * @dccpavr_ack_ackno - sequence number being acknowledged
75 * @dccpavr_ack_ptr - pointer into dccpav_buf where this record starts
76 * @dccpavr_ack_nonce - dccpav_ack_nonce at the time this record was sent
77 * @dccpavr_sent_len - lenght of the record in dccpav_buf
78 */
79struct dccp_ackvec_record {
80 struct list_head dccpavr_node;
81 u64 dccpavr_ack_seqno;
82 u64 dccpavr_ack_ackno;
83 u8 dccpavr_ack_ptr;
84 u8 dccpavr_ack_nonce;
85 u8 dccpavr_sent_len;
86};
87
88struct sock;
89struct sk_buff;
90
91#ifdef CONFIG_IP_DCCP_ACKVEC
92extern int dccp_ackvec_init(void);
93extern void dccp_ackvec_exit(void);
94
95extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
96extern void dccp_ackvec_free(struct dccp_ackvec *av);
97
98extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
99 const u64 ackno, const u8 state);
100
101extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
102 struct sock *sk, const u64 ackno);
103extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
104 const u8 opt, const u8 *value, const u8 len);
105
106extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);
107
108static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
109{
110 return av->dccpav_sent_len != av->dccpav_vec_len;
111}
112#else /* CONFIG_IP_DCCP_ACKVEC */
113static inline int dccp_ackvec_init(void)
114{
115 return 0;
116}
117
118static inline void dccp_ackvec_exit(void)
119{
120}
121
122static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
123{
124 return NULL;
125}
126
127static inline void dccp_ackvec_free(struct dccp_ackvec *av)
128{
129}
130
131static inline int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
132 const u64 ackno, const u8 state)
133{
134 return -1;
135}
136
137static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
138 struct sock *sk, const u64 ackno)
139{
140}
141
142static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
143 const u8 opt, const u8 *value, const u8 len)
144{
145 return -1;
146}
147
148static inline int dccp_insert_option_ackvec(const struct sock *sk,
149 const struct sk_buff *skb)
150{
151 return -1;
152}
153
154static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
155{
156 return 0;
157}
158#endif /* CONFIG_IP_DCCP_ACKVEC */
159#endif /* _ACKVEC_H */