tcp: Add tcp_inq to get available receive bytes on socket
Create a common kernel function to get the number of bytes available
on a TCP socket. This is based on code in INQ getsockopt and we now call
the function for that getsockopt.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index e90db85..0302636 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1816,4 +1816,28 @@
skb->truesize = 2;
}
+static inline int tcp_inq(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ int answ;
+
+ if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+ answ = 0;
+ } else if (sock_flag(sk, SOCK_URGINLINE) ||
+ !tp->urg_data ||
+ before(tp->urg_seq, tp->copied_seq) ||
+ !before(tp->urg_seq, tp->rcv_nxt)) {
+
+ answ = tp->rcv_nxt - tp->copied_seq;
+
+ /* Subtract 1, if FIN was received */
+ if (answ && sock_flag(sk, SOCK_DONE))
+ answ--;
+ } else {
+ answ = tp->urg_seq - tp->copied_seq;
+ }
+
+ return answ;
+}
+
#endif /* _TCP_H */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f9faadb..a265f00 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -556,20 +556,7 @@
return -EINVAL;
slow = lock_sock_fast(sk);
- if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
- answ = 0;
- else if (sock_flag(sk, SOCK_URGINLINE) ||
- !tp->urg_data ||
- before(tp->urg_seq, tp->copied_seq) ||
- !before(tp->urg_seq, tp->rcv_nxt)) {
-
- answ = tp->rcv_nxt - tp->copied_seq;
-
- /* Subtract 1, if FIN was received */
- if (answ && sock_flag(sk, SOCK_DONE))
- answ--;
- } else
- answ = tp->urg_seq - tp->copied_seq;
+ answ = tcp_inq(sk);
unlock_sock_fast(sk, slow);
break;
case SIOCATMARK: