[PATCH] tcp: fix FIONREAD/SIOCINQ
flat view
STALE5107d
From: Eric Dumazet <hidden>
Date: 2012-10-18 19:14:23
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: Eric Dumazet <redacted> 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 <redacted> Signed-off-by: Eric Dumazet <redacted> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <redacted> --- net/ipv4/tcp.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f32c02e..b7c2f43 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -549,14 +549,12 @@ 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);