This reverts "Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp"

as it accentally contained the wrong set of patches. These will be
submitted separately.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

1 files changed, 113 insertions, 91 deletions

diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h
index 6cdca79a99f7..bcb64fb4acef 100644
--- a/net/dccp/ackvec.h
+++ b/net/dccp/ackvec.h
@@ -3,134 +3,156 @@
 /*
  *  net/dccp/ackvec.h
  *
- *  An implementation of Ack Vectors for the DCCP protocol
- *  Copyright (c) 2007 University of Aberdeen, Scotland, UK
+ *  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/dccp.h>
 #include <linux/compiler.h>
+#include <linux/ktime.h>
 #include <linux/list.h>
 #include <linux/types.h>
 
-/*
- * Ack Vector buffer space is static, in multiples of %DCCP_SINGLE_OPT_MAXLEN,
- * the maximum size of a single Ack Vector. Setting %DCCPAV_NUM_ACKVECS to 1
- * will be sufficient for most cases of low Ack Ratios, using a value of 2 gives
- * more headroom if Ack Ratio is higher or when the sender acknowledges slowly.
- * The maximum value is bounded by the u16 types for indices and functions.
- */
-#define DCCPAV_NUM_ACKVECS      2
-#define DCCPAV_MAX_ACKVEC_LEN   (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS)
-
-/* Estimated minimum average Ack Vector length - used for updating MPS */
-#define DCCPAV_MIN_OPTLEN       16
-
-/* Threshold for coping with large bursts of losses */
-#define DCCPAV_BURST_THRESH     (DCCPAV_MAX_ACKVEC_LEN / 8)
-
-enum dccp_ackvec_states {
-        DCCPAV_RECEIVED =       0x00,
-        DCCPAV_ECN_MARKED =     0x40,
-        DCCPAV_RESERVED =       0x80,
-        DCCPAV_NOT_RECEIVED =   0xC0
-};
-#define DCCPAV_MAX_RUNLEN       0x3F
+/* 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)
 
-static inline u8 dccp_ackvec_runlen(const u8 *cell)
-{
-        return *cell & DCCPAV_MAX_RUNLEN;
-}
+#define DCCP_ACKVEC_STATE_RECEIVED      0
+#define DCCP_ACKVEC_STATE_ECN_MARKED    (1 << 6)
+#define DCCP_ACKVEC_STATE_NOT_RECEIVED  (3 << 6)
 
-static inline u8 dccp_ackvec_state(const u8 *cell)
-{
-        return *cell & ~DCCPAV_MAX_RUNLEN;
-}
+#define DCCP_ACKVEC_STATE_MASK          0xC0 /* 11000000 */
+#define DCCP_ACKVEC_LEN_MASK            0x3F /* 00111111 */
 
-/** struct dccp_ackvec - Ack Vector main data structure
+/** struct dccp_ackvec - ack vector
+ *
+ * This data structure is the one defined in RFC 4340, Appendix A.
  *
- * This implements a fixed-size circular buffer within an array and is largely
- * based on Appendix A of RFC 4340.
+ * @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
  *
- * @av_buf:        circular buffer storage area
- * @av_buf_head:   head index; begin of live portion in @av_buf
- * @av_buf_tail:   tail index; first index _after_ the live portion in @av_buf
- * @av_buf_ackno:  highest seqno of acknowledgeable packet recorded in @av_buf
- * @av_tail_ackno: lowest  seqno of acknowledgeable packet recorded in @av_buf
- * @av_buf_nonce:  ECN nonce sums, each covering subsequent segments of up to
- *                 %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf
- * @av_overflow:   if 1 then buf_head == buf_tail indicates buffer wraparound
- * @av_records:    list of %dccp_ackvec_record (Ack Vectors sent previously)
+ * 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 {
-        u8                      av_buf[DCCPAV_MAX_ACKVEC_LEN];
-        u16                     av_buf_head;
-        u16                     av_buf_tail;
-        u64                     av_buf_ackno:48;
-        u64                     av_tail_ackno:48;
-        bool                    av_buf_nonce[DCCPAV_NUM_ACKVECS];
-        u8                      av_overflow:1;
+        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 - Records information about sent Ack Vectors
+/** struct dccp_ackvec_record - ack vector record
  *
- * These list entries define the additional information which the HC-Receiver
- * keeps about recently-sent Ack Vectors; again refer to RFC 4340, Appendix A.
+ * ACK vector record as defined in Appendix A of spec.
  *
- * @avr_node:       the list node in @av_records
- * @avr_ack_seqno:  sequence number of the packet the Ack Vector was sent on
- * @avr_ack_ackno:  the Ack number that this record/Ack Vector refers to
- * @avr_ack_ptr:    pointer into @av_buf where this record starts
- * @avr_ack_runlen: run length of @avr_ack_ptr at the time of sending
- * @avr_ack_nonce:  the sum of @av_buf_nonce's at the time this record was sent
+ * The list is sorted by avr_ack_seqno
  *
- * The list as a whole is sorted in descending order 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:48;
-        u64              avr_ack_ackno:48;
+        u64              avr_ack_seqno;
+        u64              avr_ack_ackno;
         u16              avr_ack_ptr;
-        u8               avr_ack_runlen;
-        u8               avr_ack_nonce:1;
+        u16              avr_sent_len;
+        u8               avr_ack_nonce;
 };
 
-extern int  dccp_ackvec_init(void);
+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 void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb);
-extern int  dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum);
-extern void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno);
-extern u16  dccp_ackvec_buflen(const 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);
 
-static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av)
+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 av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail;
+        return 0;
 }
 
-/**
- * struct dccp_ackvec_parsed  -  Record offsets of Ack Vectors in skb
- * @vec:        start of vector (offset into skb)
- * @len:        length of @vec
- * @nonce:      whether @vec had an ECN nonce of 0 or 1
- * @node:       FIFO - arranged in descending order of ack_ackno
- * This structure is used by CCIDs to access Ack Vectors in a received skb.
- */
-struct dccp_ackvec_parsed {
-        u8               *vec,
-                         len,
-                         nonce:1;
-        struct list_head node;
-};
+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;
+}
 
-extern int dccp_ackvec_parsed_add(struct list_head *head,
-                                  u8 *vec, u8 len, u8 nonce);
-extern void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks);
+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 */