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/config.h> 15 #include <linux/compiler.h> 16 #include <linux/list.h> 17 #include <linux/time.h> 18 #include <linux/types.h> 19 20 /* Read about the ECN nonce to see why it is 253 */ 21 #define DCCP_MAX_ACKVEC_LEN 253 22 23 #define DCCP_ACKVEC_STATE_RECEIVED 0 24 #define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6) 25 #define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6) 26 27 #define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */ 28 #define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */ 29 30 /** struct dccp_ackvec - ack vector 31 * 32 * This data structure is the one defined in the DCCP draft 33 * Appendix A. 34 * 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 * 46 * @dccpav_ack_ptr - the value of buf_head at the time of acknowledgement. 47 * @dccpav_records - list of dccp_ackvec_record 48 * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0. 49 * 50 * @dccpav_time - the time in usecs 51 * @dccpav_buf - circular buffer of acknowledgeable packets 52 */ 53 struct dccp_ackvec { 54 u64 dccpav_buf_ackno; 55 struct list_head dccpav_records; 56 struct timeval dccpav_time; 57 u8 dccpav_buf_head; 58 u8 dccpav_buf_tail; 59 u8 dccpav_ack_ptr; 60 u8 dccpav_sent_len; 61 u8 dccpav_vec_len; 62 u8 dccpav_buf_nonce; 63 u8 dccpav_ack_nonce; 64 u8 dccpav_buf[DCCP_MAX_ACKVEC_LEN]; 65 }; 66 67 /** struct dccp_ackvec_record - ack vector record 68 * 69 * ACK vector record as defined in Appendix A of spec. 70 * 71 * The list is sorted by dccpavr_ack_seqno 72 * 73 * @dccpavr_node - node in dccpav_records 74 * @dccpavr_ack_seqno - sequence number of the packet this record was sent on 75 * @dccpavr_ack_ackno - sequence number being acknowledged 76 * @dccpavr_ack_ptr - pointer into dccpav_buf where this record starts 77 * @dccpavr_ack_nonce - dccpav_ack_nonce at the time this record was sent 78 * @dccpavr_sent_len - lenght of the record in dccpav_buf 79 */ 80 struct dccp_ackvec_record { 81 struct list_head dccpavr_node; 82 u64 dccpavr_ack_seqno; 83 u64 dccpavr_ack_ackno; 84 u8 dccpavr_ack_ptr; 85 u8 dccpavr_ack_nonce; 86 u8 dccpavr_sent_len; 87 }; 88 89 struct sock; 90 struct sk_buff; 91 92 #ifdef CONFIG_IP_DCCP_ACKVEC 93 extern int dccp_ackvec_init(void); 94 extern void dccp_ackvec_exit(void); 95 96 extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority); 97 extern void dccp_ackvec_free(struct dccp_ackvec *av); 98 99 extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, 100 const u64 ackno, const u8 state); 101 102 extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, 103 struct sock *sk, const u64 ackno); 104 extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, 105 const u8 opt, const u8 *value, const u8 len); 106 107 extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb); 108 109 static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) 110 { 111 return av->dccpav_sent_len != av->dccpav_vec_len; 112 } 113 #else /* CONFIG_IP_DCCP_ACKVEC */ 114 static inline int dccp_ackvec_init(void) 115 { 116 return 0; 117 } 118 119 static inline void dccp_ackvec_exit(void) 120 { 121 } 122 123 static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) 124 { 125 return NULL; 126 } 127 128 static inline void dccp_ackvec_free(struct dccp_ackvec *av) 129 { 130 } 131 132 static inline int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, 133 const u64 ackno, const u8 state) 134 { 135 return -1; 136 } 137 138 static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, 139 struct sock *sk, const u64 ackno) 140 { 141 } 142 143 static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, 144 const u8 opt, const u8 *value, const u8 len) 145 { 146 return -1; 147 } 148 149 static inline int dccp_insert_option_ackvec(const struct sock *sk, 150 const struct sk_buff *skb) 151 { 152 return -1; 153 } 154 155 static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) 156 { 157 return 0; 158 } 159 #endif /* CONFIG_IP_DCCP_ACKVEC */ 160 #endif /* _ACKVEC_H */ 161