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-rw-r--r--net/dccp/ackvec.h204
1 files changed, 113 insertions, 91 deletions
diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h
index 6cdca79a99f7..bcb64fb4acef 100644
--- a/net/dccp/ackvec.h
+++ b/net/dccp/ackvec.h
@@ -3,134 +3,156 @@
3/* 3/*
4 * net/dccp/ackvec.h 4 * net/dccp/ackvec.h
5 * 5 *
6 * An implementation of Ack Vectors for the DCCP protocol 6 * An implementation of the DCCP protocol
7 * Copyright (c) 2007 University of Aberdeen, Scotland, UK
8 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@mandriva.com> 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 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 10 * under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation. 11 * published by the Free Software Foundation.
12 */ 12 */
13 13
14#include <linux/dccp.h>
15#include <linux/compiler.h> 14#include <linux/compiler.h>
15#include <linux/ktime.h>
16#include <linux/list.h> 16#include <linux/list.h>
17#include <linux/types.h> 17#include <linux/types.h>
18 18
19/* 19/* Read about the ECN nonce to see why it is 253 */
20 * Ack Vector buffer space is static, in multiples of %DCCP_SINGLE_OPT_MAXLEN, 20#define DCCP_MAX_ACKVEC_OPT_LEN 253
21 * the maximum size of a single Ack Vector. Setting %DCCPAV_NUM_ACKVECS to 1 21/* We can spread an ack vector across multiple options */
22 * will be sufficient for most cases of low Ack Ratios, using a value of 2 gives 22#define DCCP_MAX_ACKVEC_LEN (DCCP_MAX_ACKVEC_OPT_LEN * 2)
23 * more headroom if Ack Ratio is higher or when the sender acknowledges slowly.
24 * The maximum value is bounded by the u16 types for indices and functions.
25 */
26#define DCCPAV_NUM_ACKVECS 2
27#define DCCPAV_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS)
28
29/* Estimated minimum average Ack Vector length - used for updating MPS */
30#define DCCPAV_MIN_OPTLEN 16
31
32/* Threshold for coping with large bursts of losses */
33#define DCCPAV_BURST_THRESH (DCCPAV_MAX_ACKVEC_LEN / 8)
34
35enum dccp_ackvec_states {
36 DCCPAV_RECEIVED = 0x00,
37 DCCPAV_ECN_MARKED = 0x40,
38 DCCPAV_RESERVED = 0x80,
39 DCCPAV_NOT_RECEIVED = 0xC0
40};
41#define DCCPAV_MAX_RUNLEN 0x3F
42 23
43static inline u8 dccp_ackvec_runlen(const u8 *cell) 24#define DCCP_ACKVEC_STATE_RECEIVED 0
44{ 25#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6)
45 return *cell & DCCPAV_MAX_RUNLEN; 26#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6)
46}
47 27
48static inline u8 dccp_ackvec_state(const u8 *cell) 28#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */
49{ 29#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */
50 return *cell & ~DCCPAV_MAX_RUNLEN;
51}
52 30
53/** struct dccp_ackvec - Ack Vector main data structure 31/** struct dccp_ackvec - ack vector
32 *
33 * This data structure is the one defined in RFC 4340, Appendix A.
54 * 34 *
55 * This implements a fixed-size circular buffer within an array and is largely 35 * @av_buf_head - circular buffer head
56 * based on Appendix A of RFC 4340. 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
40 * by the buffer with State 0
57 * 41 *
58 * @av_buf: circular buffer storage area 42 * Additionally, the HC-Receiver must keep some information about the
59 * @av_buf_head: head index; begin of live portion in @av_buf 43 * Ack Vectors it has recently sent. For each packet sent carrying an
60 * @av_buf_tail: tail index; first index _after_ the live portion in @av_buf 44 * Ack Vector, it remembers four variables:
61 * @av_buf_ackno: highest seqno of acknowledgeable packet recorded in @av_buf 45 *
62 * @av_tail_ackno: lowest seqno of acknowledgeable packet recorded in @av_buf 46 * @av_records - list of dccp_ackvec_record
63 * @av_buf_nonce: ECN nonce sums, each covering subsequent segments of up to 47 * @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
64 * %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf 48 *
65 * @av_overflow: if 1 then buf_head == buf_tail indicates buffer wraparound 49 * @av_time - the time in usecs
66 * @av_records: list of %dccp_ackvec_record (Ack Vectors sent previously) 50 * @av_buf - circular buffer of acknowledgeable packets
67 */ 51 */
68struct dccp_ackvec { 52struct dccp_ackvec {
69 u8 av_buf[DCCPAV_MAX_ACKVEC_LEN]; 53 u64 av_buf_ackno;
70 u16 av_buf_head;
71 u16 av_buf_tail;
72 u64 av_buf_ackno:48;
73 u64 av_tail_ackno:48;
74 bool av_buf_nonce[DCCPAV_NUM_ACKVECS];
75 u8 av_overflow:1;
76 struct list_head av_records; 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];
77}; 61};
78 62
79/** struct dccp_ackvec_record - Records information about sent Ack Vectors 63/** struct dccp_ackvec_record - ack vector record
80 * 64 *
81 * These list entries define the additional information which the HC-Receiver 65 * ACK vector record as defined in Appendix A of spec.
82 * keeps about recently-sent Ack Vectors; again refer to RFC 4340, Appendix A.
83 * 66 *
84 * @avr_node: the list node in @av_records 67 * The list is sorted by avr_ack_seqno
85 * @avr_ack_seqno: sequence number of the packet the Ack Vector was sent on
86 * @avr_ack_ackno: the Ack number that this record/Ack Vector refers to
87 * @avr_ack_ptr: pointer into @av_buf where this record starts
88 * @avr_ack_runlen: run length of @avr_ack_ptr at the time of sending
89 * @avr_ack_nonce: the sum of @av_buf_nonce's at the time this record was sent
90 * 68 *
91 * The list as a whole is sorted in descending order by @avr_ack_seqno. 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
92 */ 75 */
93struct dccp_ackvec_record { 76struct dccp_ackvec_record {
94 struct list_head avr_node; 77 struct list_head avr_node;
95 u64 avr_ack_seqno:48; 78 u64 avr_ack_seqno;
96 u64 avr_ack_ackno:48; 79 u64 avr_ack_ackno;
97 u16 avr_ack_ptr; 80 u16 avr_ack_ptr;
98 u8 avr_ack_runlen; 81 u16 avr_sent_len;
99 u8 avr_ack_nonce:1; 82 u8 avr_ack_nonce;
100}; 83};
101 84
102extern int dccp_ackvec_init(void); 85struct sock;
86struct sk_buff;
87
88#ifdef CONFIG_IP_DCCP_ACKVEC
89extern int dccp_ackvec_init(void);
103extern void dccp_ackvec_exit(void); 90extern void dccp_ackvec_exit(void);
104 91
105extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority); 92extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
106extern void dccp_ackvec_free(struct dccp_ackvec *av); 93extern void dccp_ackvec_free(struct dccp_ackvec *av);
107 94
108extern void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb); 95extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
109extern int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum); 96 const u64 ackno, const u8 state);
110extern void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno); 97
111extern u16 dccp_ackvec_buflen(const struct dccp_ackvec *av); 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,
101 u64 *ackno, const u8 opt,
102 const u8 *value, const u8 len);
112 103
113static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av) 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{
108 return av->av_vec_len;
109}
110#else /* CONFIG_IP_DCCP_ACKVEC */
111static inline int dccp_ackvec_init(void)
114{ 112{
115 return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail; 113 return 0;
116} 114}
117 115
118/** 116static inline void dccp_ackvec_exit(void)
119 * struct dccp_ackvec_parsed - Record offsets of Ack Vectors in skb 117{
120 * @vec: start of vector (offset into skb) 118}
121 * @len: length of @vec 119
122 * @nonce: whether @vec had an ECN nonce of 0 or 1 120static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
123 * @node: FIFO - arranged in descending order of ack_ackno 121{
124 * This structure is used by CCIDs to access Ack Vectors in a received skb. 122 return NULL;
125 */ 123}
126struct dccp_ackvec_parsed { 124
127 u8 *vec, 125static inline void dccp_ackvec_free(struct dccp_ackvec *av)
128 len, 126{
129 nonce:1; 127}
130 struct list_head node; 128
131}; 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}
132 134
133extern int dccp_ackvec_parsed_add(struct list_head *head, 135static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
134 u8 *vec, u8 len, u8 nonce); 136 struct sock *sk, const u64 ackno)
135extern void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks); 137{
138}
139
140static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
141 const u64 *ackno, const u8 opt,
142 const u8 *value, const u8 len)
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 */
136#endif /* _ACKVEC_H */ 158#endif /* _ACKVEC_H */
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-22 04:29:00 -0500