[TCP]: Abstract out all write queue operations.

This allows the write queue implementation to be changed,
for example, to one which allows fast interval searching.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 114 insertions, 0 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 181c0600af1c..6dacc352dcf1 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1162,6 +1162,120 @@ static inline void		tcp_put_md5sig_pool(void)
         put_cpu();
 }
 
+/* write queue abstraction */
+static inline void tcp_write_queue_purge(struct sock *sk)
+{
+        struct sk_buff *skb;
+
+        while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
+                sk_stream_free_skb(sk, skb);
+        sk_stream_mem_reclaim(sk);
+}
+
+static inline struct sk_buff *tcp_write_queue_head(struct sock *sk)
+{
+        struct sk_buff *skb = sk->sk_write_queue.next;
+        if (skb == (struct sk_buff *) &sk->sk_write_queue)
+                return NULL;
+        return skb;
+}
+
+static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk)
+{
+        struct sk_buff *skb = sk->sk_write_queue.prev;
+        if (skb == (struct sk_buff *) &sk->sk_write_queue)
+                return NULL;
+        return skb;
+}
+
+static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb)
+{
+        return skb->next;
+}
+
+#define tcp_for_write_queue(skb, sk)                                    \
+                for (skb = (sk)->sk_write_queue.next;                   \
+                     (skb != (struct sk_buff *)&(sk)->sk_write_queue);  \
+                     skb = skb->next)
+
+#define tcp_for_write_queue_from(skb, sk)                               \
+                for (; (skb != (struct sk_buff *)&(sk)->sk_write_queue);\
+                     skb = skb->next)
+
+static inline struct sk_buff *tcp_send_head(struct sock *sk)
+{
+        return sk->sk_send_head;
+}
+
+static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb)
+{
+        sk->sk_send_head = skb->next;
+        if (sk->sk_send_head == (struct sk_buff *)&sk->sk_write_queue)
+                sk->sk_send_head = NULL;
+}
+
+static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
+{
+        if (sk->sk_send_head == skb_unlinked)
+                sk->sk_send_head = NULL;
+}
+
+static inline void tcp_init_send_head(struct sock *sk)
+{
+        sk->sk_send_head = NULL;
+}
+
+static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
+{
+        __skb_queue_tail(&sk->sk_write_queue, skb);
+}
+
+static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
+{
+        __tcp_add_write_queue_tail(sk, skb);
+
+        /* Queue it, remembering where we must start sending. */
+        if (sk->sk_send_head == NULL)
+                sk->sk_send_head = skb;
+}
+
+static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb)
+{
+        __skb_queue_head(&sk->sk_write_queue, skb);
+}
+
+/* Insert buff after skb on the write queue of sk.  */
+static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
+                                                struct sk_buff *buff,
+                                                struct sock *sk)
+{
+        __skb_append(skb, buff, &sk->sk_write_queue);
+}
+
+/* Insert skb between prev and next on the write queue of sk.  */
+static inline void tcp_insert_write_queue_before(struct sk_buff *new,
+                                                  struct sk_buff *skb,
+                                                  struct sock *sk)
+{
+        __skb_insert(new, skb->prev, skb, &sk->sk_write_queue);
+}
+
+static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk)
+{
+        __skb_unlink(skb, &sk->sk_write_queue);
+}
+
+static inline int tcp_skb_is_last(const struct sock *sk,
+                                  const struct sk_buff *skb)
+{
+        return skb->next == (struct sk_buff *)&sk->sk_write_queue;
+}
+
+static inline int tcp_write_queue_empty(struct sock *sk)
+{
+        return skb_queue_empty(&sk->sk_write_queue);
+}
+
 /* /proc */
 enum tcp_seq_states {
         TCP_SEQ_STATE_LISTENING,