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Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -07001#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
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070014#include <linux/compiler.h>
Arnaldo Carvalho de Melob8bda9d2007-08-19 17:17:25 -070015#include <linux/ktime.h>
Andrea Bittau02bcf282006-03-20 17:19:55 -080016#include <linux/list.h>
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070017#include <linux/types.h>
18
19/* Read about the ECN nonce to see why it is 253 */
Andrea Bittaubdf13d22006-11-24 13:02:42 -020020#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)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070023
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 *
Gerrit Renker0e64e942006-10-24 16:17:51 -070033 * This data structure is the one defined in RFC 4340, Appendix A.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070034 *
35 * @dccpav_buf_head - circular buffer head
36 * @dccpav_buf_tail - circular buffer tail
37 * @dccpav_buf_ackno - ack # of the most recent packet acknowledgeable in the
38 * buffer (i.e. %dccpav_buf_head)
39 * @dccpav_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
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 *
Andrea Bittau02bcf282006-03-20 17:19:55 -080046 * @dccpav_records - list of dccp_ackvec_record
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070047 * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
48 *
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070049 * @dccpav_time - the time in usecs
50 * @dccpav_buf - circular buffer of acknowledgeable packets
51 */
52struct dccp_ackvec {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070053 u64 dccpav_buf_ackno;
Andrea Bittau02bcf282006-03-20 17:19:55 -080054 struct list_head dccpav_records;
Arnaldo Carvalho de Melob8bda9d2007-08-19 17:17:25 -070055 ktime_t dccpav_time;
Andrea Bittaubdf13d22006-11-24 13:02:42 -020056 u16 dccpav_buf_head;
57 u16 dccpav_vec_len;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070058 u8 dccpav_buf_nonce;
59 u8 dccpav_ack_nonce;
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -080060 u8 dccpav_buf[DCCP_MAX_ACKVEC_LEN];
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070061};
62
Andrea Bittau02bcf282006-03-20 17:19:55 -080063/** struct dccp_ackvec_record - ack vector record
64 *
65 * ACK vector record as defined in Appendix A of spec.
66 *
67 * The list is sorted by dccpavr_ack_seqno
68 *
69 * @dccpavr_node - node in dccpav_records
70 * @dccpavr_ack_seqno - sequence number of the packet this record was sent on
71 * @dccpavr_ack_ackno - sequence number being acknowledged
72 * @dccpavr_ack_ptr - pointer into dccpav_buf where this record starts
73 * @dccpavr_ack_nonce - dccpav_ack_nonce at the time this record was sent
74 * @dccpavr_sent_len - lenght of the record in dccpav_buf
75 */
76struct dccp_ackvec_record {
77 struct list_head dccpavr_node;
78 u64 dccpavr_ack_seqno;
79 u64 dccpavr_ack_ackno;
Andrea Bittaubdf13d22006-11-24 13:02:42 -020080 u16 dccpavr_ack_ptr;
81 u16 dccpavr_sent_len;
Andrea Bittau02bcf282006-03-20 17:19:55 -080082 u8 dccpavr_ack_nonce;
Andrea Bittau02bcf282006-03-20 17:19:55 -080083};
84
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070085struct sock;
86struct sk_buff;
87
88#ifdef CONFIG_IP_DCCP_ACKVEC
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -080089extern int dccp_ackvec_init(void);
90extern void dccp_ackvec_exit(void);
91
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -080092extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070093extern 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,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200101 u64 *ackno, const u8 opt,
102 const u8 *value, const u8 len);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700103
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{
Andrea Bittau4a0a50fb42006-09-19 13:06:16 -0700108 return av->dccpav_vec_len;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700109}
110#else /* CONFIG_IP_DCCP_ACKVEC */
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800111static inline int dccp_ackvec_init(void)
112{
113 return 0;
114}
115
116static inline void dccp_ackvec_exit(void)
117{
118}
119
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800120static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700121{
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,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200141 const u64 *ackno, const u8 opt,
142 const u8 *value, const u8 len)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700143{
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 */