6 * An implementation of the DCCP protocol
7 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@mandriva.com>
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.
14 #include <linux/compiler.h>
15 #include <linux/list.h>
16 #include <linux/time.h>
17 #include <linux/types.h>
19 /* Read about the ECN nonce to see why it is 253 */
20 #define DCCP_MAX_ACKVEC_LEN 253
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)
26 #define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */
27 #define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */
29 /** struct dccp_ackvec - ack vector
31 * This data structure is the one defined in RFC 4340, Appendix A.
33 * @dccpav_buf_head - circular buffer head
34 * @dccpav_buf_tail - circular buffer tail
35 * @dccpav_buf_ackno - ack # of the most recent packet acknowledgeable in the
36 * buffer (i.e. %dccpav_buf_head)
37 * @dccpav_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
38 * by the buffer with State 0
40 * Additionally, the HC-Receiver must keep some information about the
41 * Ack Vectors it has recently sent. For each packet sent carrying an
42 * Ack Vector, it remembers four variables:
44 * @dccpav_records - list of dccp_ackvec_record
45 * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
47 * @dccpav_time - the time in usecs
48 * @dccpav_buf - circular buffer of acknowledgeable packets
52 struct list_head dccpav_records;
53 struct timeval dccpav_time;
58 u8 dccpav_buf[DCCP_MAX_ACKVEC_LEN];
61 /** struct dccp_ackvec_record - ack vector record
63 * ACK vector record as defined in Appendix A of spec.
65 * The list is sorted by dccpavr_ack_seqno
67 * @dccpavr_node - node in dccpav_records
68 * @dccpavr_ack_seqno - sequence number of the packet this record was sent on
69 * @dccpavr_ack_ackno - sequence number being acknowledged
70 * @dccpavr_ack_ptr - pointer into dccpav_buf where this record starts
71 * @dccpavr_ack_nonce - dccpav_ack_nonce at the time this record was sent
72 * @dccpavr_sent_len - lenght of the record in dccpav_buf
74 struct dccp_ackvec_record {
75 struct list_head dccpavr_node;
76 u64 dccpavr_ack_seqno;
77 u64 dccpavr_ack_ackno;
86 #ifdef CONFIG_IP_DCCP_ACKVEC
87 extern int dccp_ackvec_init(void);
88 extern void dccp_ackvec_exit(void);
90 extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
91 extern void dccp_ackvec_free(struct dccp_ackvec *av);
93 extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
94 const u64 ackno, const u8 state);
96 extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
97 struct sock *sk, const u64 ackno);
98 extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
99 const u8 opt, const u8 *value, const u8 len);
101 extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);
103 static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
105 return av->dccpav_vec_len;
107 #else /* CONFIG_IP_DCCP_ACKVEC */
108 static inline int dccp_ackvec_init(void)
113 static inline void dccp_ackvec_exit(void)
117 static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
122 static inline void dccp_ackvec_free(struct dccp_ackvec *av)
126 static inline int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
127 const u64 ackno, const u8 state)
132 static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
133 struct sock *sk, const u64 ackno)
137 static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
138 const u8 opt, const u8 *value, const u8 len)
143 static inline int dccp_insert_option_ackvec(const struct sock *sk,
144 const struct sk_buff *skb)
149 static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
153 #endif /* CONFIG_IP_DCCP_ACKVEC */
154 #endif /* _ACKVEC_H */