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>
This commit is contained in:
Tom Herbert 2016-03-07 14:11:05 -08:00 committed by David S. Miller
parent fa9835e52e
commit 473bd239b8
2 changed files with 25 additions and 14 deletions

View File

@ -1816,4 +1816,28 @@ static inline void skb_set_tcp_pure_ack(struct sk_buff *skb)
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 */

View File

@ -556,20 +556,7 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
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: