+/* Start sequence of the highest skb with SACKed bit, valid only if
+ * sacked > 0 or when the caller has ensured validity by itself.
+ */
+static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp)
+{
+ if (!tp->sacked_out)
+ return tp->snd_una;
+
+ if (tp->highest_sack == NULL)
+ return tp->snd_nxt;
+
+ return TCP_SKB_CB(tp->highest_sack)->seq;
+}
+
+static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb)
+{
+ tcp_sk(sk)->highest_sack = tcp_skb_is_last(sk, skb) ? NULL :
+ tcp_write_queue_next(sk, skb);
+}
+
+static inline struct sk_buff *tcp_highest_sack(struct sock *sk)
+{
+ return tcp_sk(sk)->highest_sack;
+}
+
+static inline void tcp_highest_sack_reset(struct sock *sk)
+{
+ tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk);
+}
+
+/* Called when old skb is about to be deleted (to be combined with new skb) */
+static inline void tcp_highest_sack_combine(struct sock *sk,
+ struct sk_buff *old,
+ struct sk_buff *new)
+{
+ if (tcp_sk(sk)->sacked_out && (old == tcp_sk(sk)->highest_sack))
+ tcp_sk(sk)->highest_sack = new;
+}
+