This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / net / dccp / ackvec.h

diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h
new file mode 100644 (file)
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+++ b/net/dccp/ackvec.h
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+#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/list.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_ptr - the value of buf_head at the time of acknowledgement.
+ * @dccpav_records - list of dccp_ackvec_record
+ * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
+ *
+ * @dccpav_time                - the time in usecs
+ * @dccpav_buf - circular buffer of acknowledgeable packets
+ */
+struct dccp_ackvec {
+       u64             dccpav_buf_ackno;
+       struct list_head dccpav_records;
+       struct timeval  dccpav_time;
+       u8              dccpav_buf_head;
+       u8              dccpav_buf_tail;
+       u8              dccpav_ack_ptr;
+       u8              dccpav_sent_len;
+       u8              dccpav_vec_len;
+       u8              dccpav_buf_nonce;
+       u8              dccpav_ack_nonce;
+       u8              dccpav_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 dccpavr_ack_seqno
+ *
+ * @dccpavr_node - node in dccpav_records
+ * @dccpavr_ack_seqno - sequence number of the packet this record was sent on
+ * @dccpavr_ack_ackno - sequence number being acknowledged
+ * @dccpavr_ack_ptr - pointer into dccpav_buf where this record starts
+ * @dccpavr_ack_nonce - dccpav_ack_nonce at the time this record was sent
+ * @dccpavr_sent_len - lenght of the record in dccpav_buf
+ */
+struct dccp_ackvec_record {
+       struct list_head dccpavr_node;
+       u64              dccpavr_ack_seqno;
+       u64              dccpavr_ack_ackno;
+       u8               dccpavr_ack_ptr;
+       u8               dccpavr_ack_nonce;
+       u8               dccpavr_sent_len;
+};
+
+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,
+                            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 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 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 */