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| author | Soheil Hassas Yeganeh <soheil@google.com> | 2019-03-06 13:01:36 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-19 13:10:54 +0100 |
| commit | 75c9b039f9bdf59f4fd74b1cf3db7321497653fa (patch) | |
| tree | f88d6ab873221f6b74d75e7965369bcee3683233 /net/ipv4 | |
| parent | 05ad31a85e96bba6c2725f41f91f910d6a4ec21e (diff) | |
| download | talos-obmc-linux-75c9b039f9bdf59f4fd74b1cf3db7321497653fa.tar.gz talos-obmc-linux-75c9b039f9bdf59f4fd74b1cf3db7321497653fa.zip | |
tcp: do not report TCP_CM_INQ of 0 for closed connections
[ Upstream commit 6466e715651f9f358e60c5ea4880e4731325827f ]
Returning 0 as inq to userspace indicates there is no more data to
read, and the application needs to wait for EPOLLIN. For a connection
that has received FIN from the remote peer, however, the application
must continue reading until getting EOF (return value of 0
from tcp_recvmsg) or an error, if edge-triggered epoll (EPOLLET) is
being used. Otherwise, the application will never receive a new
EPOLLIN, since there is no epoll edge after the FIN.
Return 1 when there is no data left on the queue but the
connection has received FIN, so that the applications continue
reading.
Fixes: b75eba76d3d72 (tcp: send in-queue bytes in cmsg upon read)
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index cf3c5095c10e..ce365cbba1d1 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1914,6 +1914,11 @@ static int tcp_inq_hint(struct sock *sk) inq = tp->rcv_nxt - tp->copied_seq; release_sock(sk); } + /* After receiving a FIN, tell the user-space to continue reading + * by returning a non-zero inq. + */ + if (inq == 0 && sock_flag(sk, SOCK_DONE)) + inq = 1; return inq; } |
