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Diffstat (limited to 'net/dccp/ackvec.h')
| -rw-r--r-- | net/dccp/ackvec.h | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h new file mode 100644 index 0000000..bcb64fb --- /dev/null +++ b/net/dccp/ackvec.h @@ -0,0 +1,158 @@ +#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/compiler.h> +#include <linux/ktime.h> +#include <linux/list.h> +#include <linux/types.h> + +/* Read about the ECN nonce to see why it is 253 */ +#define DCCP_MAX_ACKVEC_OPT_LEN 253 +/* We can spread an ack vector across multiple options */ +#define DCCP_MAX_ACKVEC_LEN (DCCP_MAX_ACKVEC_OPT_LEN * 2) + +#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 RFC 4340, Appendix A. + * + * @av_buf_head - circular buffer head + * @av_buf_tail - circular buffer tail + * @av_buf_ackno - ack # of the most recent packet acknowledgeable in the + * buffer (i.e. %av_buf_head) + * @av_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: + * + * @av_records - list of dccp_ackvec_record + * @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0. + * + * @av_time - the time in usecs + * @av_buf - circular buffer of acknowledgeable packets + */ +struct dccp_ackvec { + u64 av_buf_ackno; + struct list_head av_records; + ktime_t av_time; + u16 av_buf_head; + u16 av_vec_len; + u8 av_buf_nonce; + u8 av_ack_nonce; + u8 av_buf[DCCP_MAX_ACKVEC_LEN]; +}; + +/** struct dccp_ackvec_record - ack vector record + * + * ACK vector record as defined in Appendix A of spec. + * + * The list is sorted by avr_ack_seqno + * + * @avr_node - node in av_records + * @avr_ack_seqno - sequence number of the packet this record was sent on + * @avr_ack_ackno - sequence number being acknowledged + * @avr_ack_ptr - pointer into av_buf where this record starts + * @avr_ack_nonce - av_ack_nonce at the time this record was sent + * @avr_sent_len - lenght of the record in av_buf + */ +struct dccp_ackvec_record { + struct list_head avr_node; + u64 avr_ack_seqno; + u64 avr_ack_ackno; + u16 avr_ack_ptr; + u16 avr_sent_len; + u8 avr_ack_nonce; +}; + +struct sock; +struct sk_buff; + +#ifdef CONFIG_IP_DCCP_ACKVEC +extern int dccp_ackvec_init(void); +extern void dccp_ackvec_exit(void); + +extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t 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, + u64 *ackno, 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->av_vec_len; +} +#else /* CONFIG_IP_DCCP_ACKVEC */ +static inline int dccp_ackvec_init(void) +{ + return 0; +} + +static inline void dccp_ackvec_exit(void) +{ +} + +static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t 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 u64 *ackno, 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 */ |
