diff options
| author | Eric Dumazet <edumazet@google.com> | 2012-10-18 09:14:12 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-17 13:18:52 -0800 |
| commit | 48ff12fe363a34b854b1703ecb62d57cf9c65e9c (patch) | |
| tree | 7d2b3c92f13b4f6944a6ed878c549ba7dab47567 | |
| parent | dd2a911bc67a0c2ccf80f89f9aeb8e26fcd45ab1 (diff) | |
| download | lwn-48ff12fe363a34b854b1703ecb62d57cf9c65e9c.tar.gz lwn-48ff12fe363a34b854b1703ecb62d57cf9c65e9c.zip | |
tcp: fix FIONREAD/SIOCINQ
[ Upstream commit a3374c42aa5f7237e87ff3b0622018636b0c847e ]
tcp_ioctl() tries to take into account if tcp socket received a FIN
to report correct number bytes in receive queue.
But its flaky because if the application ate the last skb,
we return 1 instead of 0.
Correct way to detect that FIN was received is to test SOCK_DONE.
Reported-by: Elliot Hughes <enh@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/tcp.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 5f6419341821..49dd99307815 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -548,14 +548,12 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) !tp->urg_data || before(tp->urg_seq, tp->copied_seq) || !before(tp->urg_seq, tp->rcv_nxt)) { - struct sk_buff *skb; answ = tp->rcv_nxt - tp->copied_seq; - /* Subtract 1, if FIN is in queue. */ - skb = skb_peek_tail(&sk->sk_receive_queue); - if (answ && skb) - answ -= tcp_hdr(skb)->fin; + /* Subtract 1, if FIN was received */ + if (answ && sock_flag(sk, SOCK_DONE)) + answ--; } else answ = tp->urg_seq - tp->copied_seq; release_sock(sk); |