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Diffstat (limited to 'net/dccp/ackvec.h')
| -rw-r--r-- | net/dccp/ackvec.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h new file mode 100644 index 000000000000..8ca51c9191f7 --- /dev/null +++ b/net/dccp/ackvec.h @@ -0,0 +1,133 @@ +#ifndef _ACKVEC_H +#define _ACKVEC_H +/* + * net/dccp/ackvec.h + * + * An implementation of the DCCP protocol + * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@mandriva.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/config.h> +#include <linux/compiler.h> +#include <linux/time.h> +#include <linux/types.h> + +/* Read about the ECN nonce to see why it is 253 */ +#define DCCP_MAX_ACKVEC_LEN 253 + +#define DCCP_ACKVEC_STATE_RECEIVED 0 +#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6) +#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6) + +#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */ +#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */ + +/** struct dccp_ackvec - ack vector + * + * This data structure is the one defined in the DCCP draft + * Appendix A. + * + * @dccpav_buf_head - circular buffer head + * @dccpav_buf_tail - circular buffer tail + * @dccpav_buf_ackno - ack # of the most recent packet acknowledgeable in the + * buffer (i.e. %dccpav_buf_head) + * @dccpav_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked + * by the buffer with State 0 + * + * Additionally, the HC-Receiver must keep some information about the + * Ack Vectors it has recently sent. For each packet sent carrying an + * Ack Vector, it remembers four variables: + * + * @dccpav_ack_seqno - the Sequence Number used for the packet + * (HC-Receiver seqno) + * @dccpav_ack_ptr - the value of buf_head at the time of acknowledgement. + * @dccpav_ack_ackno - the Acknowledgement Number used for the packet + * (HC-Sender seqno) + * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0. + * + * @dccpav_buf_len - circular buffer length + * @dccpav_time - the time in usecs + * @dccpav_buf - circular buffer of acknowledgeable packets + */ +struct dccp_ackvec { + unsigned int dccpav_buf_head; + unsigned int dccpav_buf_tail; + u64 dccpav_buf_ackno; + u64 dccpav_ack_seqno; + u64 dccpav_ack_ackno; + unsigned int dccpav_ack_ptr; + unsigned int dccpav_sent_len; + unsigned int dccpav_vec_len; + unsigned int dccpav_buf_len; + struct timeval dccpav_time; + u8 dccpav_buf_nonce; + u8 dccpav_ack_nonce; + u8 dccpav_buf[0]; +}; + +struct sock; +struct sk_buff; + +#ifdef CONFIG_IP_DCCP_ACKVEC +extern struct dccp_ackvec *dccp_ackvec_alloc(unsigned int len, + const unsigned int __nocast priority); +extern void dccp_ackvec_free(struct dccp_ackvec *av); + +extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, + const u64 ackno, const u8 state); + +extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, + struct sock *sk, const u64 ackno); +extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, + const u8 opt, const u8 *value, const u8 len); + +extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb); + +static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) +{ + return av->dccpav_sent_len != av->dccpav_vec_len; +} +#else /* CONFIG_IP_DCCP_ACKVEC */ +static inline struct dccp_ackvec *dccp_ackvec_alloc(unsigned int len, + const unsigned int __nocast priority) +{ + return NULL; +} + +static inline void dccp_ackvec_free(struct dccp_ackvec *av) +{ +} + +static inline int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, + const u64 ackno, const u8 state) +{ + return -1; +} + +static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, + struct sock *sk, const u64 ackno) +{ +} + +static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, + const u8 opt, const u8 *value, const u8 len) +{ + return -1; +} + +static inline int dccp_insert_option_ackvec(const struct sock *sk, + const struct sk_buff *skb) +{ + return -1; +} + +static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) +{ + return 0; +} +#endif /* CONFIG_IP_DCCP_ACKVEC */ +#endif /* _ACKVEC_H */ |