dccp ccid-2: Separate option parsing from CCID processing

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

diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h
index 3e894a0173a76817ec52214fecfe7af9c8accf98..e2ab0627a5ff6c2a63d35cf7641e6ac5dbbd5f4e 100644 (file)
--- a/net/dccp/ackvec.h
+++ b/net/dccp/ackvec.h
@@ -21,6 +21,7 @@
  * 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)
@@ -28,6 +29,9 @@
 /* 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,
@@ -55,19 +59,21 @@ static inline u8 dccp_ackvec_state(const u8 *cell)
  * @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)
- * @av_veclen:    length of the live portion of @av_buf
  */
 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;
        struct list_head        av_records;
-       u16                     av_vec_len;
 };
 
 /** struct dccp_ackvec_record - Records information about sent Ack Vectors
@@ -93,28 +99,38 @@ struct dccp_ackvec_record {
        u8               avr_ack_nonce:1;
 };
 
-struct sock;
-struct sk_buff;
-
 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 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);
 
-static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
+static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av)
 {
-       return av->av_vec_len;
+       return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail;
 }
+
+/**
+ * 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;
+};
+
+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);
 #endif /* _ACKVEC_H */