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 */ 52 struct 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 */ 79 struct 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 88 struct sock; 89 struct sk_buff; 90 91 #ifdef CONFIG_IP_DCCP_ACKVEC 92 extern int dccp_ackvec_init(void); 93 extern void dccp_ackvec_exit(void); 94 95 extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority); 96 extern void dccp_ackvec_free(struct dccp_ackvec *av); 97 98 extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, 99 const u64 ackno, const u8 state); 100 101 extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, 102 struct sock *sk, const u64 ackno); 103 extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, 104 const u8 opt, const u8 *value, const u8 len); 105 106 extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb); 107 108 static 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 */ 113 static inline int dccp_ackvec_init(void) 114 { 115 return 0; 116 } 117 118 static inline void dccp_ackvec_exit(void) 119 { 120 } 121 122 static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) 123 { 124 return NULL; 125 } 126 127 static inline void dccp_ackvec_free(struct dccp_ackvec *av) 128 { 129 } 130 131 static 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 } 136 137 static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, 138 struct sock *sk, const u64 ackno) 139 { 140 } 141 142 static 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 } 147 148 static inline int dccp_insert_option_ackvec(const struct sock *sk, 149 const struct sk_buff *skb) 150 { 151 return -1; 152 } 153 154 static 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 */ 160