From: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" <longpeng2@huawei.com>
To: Stefano Garzarella <sgarzare@redhat.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Gonglei (Arei)" <arei.gonglei@huawei.com>,
"Subo (Subo,
Cloud Infrastructure Service Product Dept.)" <subo7@huawei.com>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jorgen Hansen <jhansen@vmware.com>,
Norbert Slusarek <nslusarek@gmx.net>,
Andra Paraschiv <andraprs@amazon.com>,
Colin Ian King <colin.king@canonical.com>,
"David Brazdil" <dbrazdil@google.com>,
Alexander Popov <alex.popov@linux.com>,
"lixianming (E)" <lixianming5@huawei.com>
Subject: RE: [RFC] vsock: notify server to shutdown when client has pending signal
Date: Thu, 13 May 2021 10:35:57 +0000 [thread overview]
Message-ID: <558d53dd31dc4841b94c4ec35249ac80@huawei.com> (raw)
In-Reply-To: <20210513094143.pir5vzsludut3xdc@steredhat>
Hi Stefano,
> -----Original Message-----
> From: Stefano Garzarella [mailto:sgarzare@redhat.com]
> Sent: Thursday, May 13, 2021 5:42 PM
> To: Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
> <longpeng2@huawei.com>
> Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Gonglei (Arei)
> <arei.gonglei@huawei.com>; Subo (Subo, Cloud Infrastructure Service Product
> Dept.) <subo7@huawei.com>; David S . Miller <davem@davemloft.net>; Jakub
> Kicinski <kuba@kernel.org>; Jorgen Hansen <jhansen@vmware.com>; Norbert
> Slusarek <nslusarek@gmx.net>; Andra Paraschiv <andraprs@amazon.com>;
> Colin Ian King <colin.king@canonical.com>; David Brazdil
> <dbrazdil@google.com>; Alexander Popov <alex.popov@linux.com>;
> lixianming (E) <lixianming5@huawei.com>
> Subject: Re: [RFC] vsock: notify server to shutdown when client has pending
> signal
>
> Hi,
> thanks for this patch, comments below...
>
> On Tue, May 11, 2021 at 05:41:27PM +0800, Longpeng(Mike) wrote:
> >The client's sk_state will be set to TCP_ESTABLISHED if the server
> >replay the client's connect request.
> >However, if the client has pending signal, its sk_state will be set to
> >TCP_CLOSE without notify the server, so the server will hold the
> >corrupt connection.
> >
> > client server
> >
> >1. sk_state=TCP_SYN_SENT |
> >2. call ->connect() |
> >3. wait reply |
> > | 4. sk_state=TCP_ESTABLISHED
> > | 5. insert to connected list
> > | 6. reply to the client
> >7. sk_state=TCP_ESTABLISHED |
> >8. insert to connected list |
> >9. *signal pending* <--------------------- the user kill client
> >10. sk_state=TCP_CLOSE |
> >client is exiting... |
> >11. call ->release() |
> > virtio_transport_close
> > if (!(sk->sk_state == TCP_ESTABLISHED ||
> > sk->sk_state == TCP_CLOSING))
> > return true; <------------- return at here As a result, the server
> >cannot notice the connection is corrupt.
> >So the client should notify the peer in this case.
> >
> >Cc: David S. Miller <davem@davemloft.net>
> >Cc: Jakub Kicinski <kuba@kernel.org>
> >Cc: Stefano Garzarella <sgarzare@redhat.com>
> >Cc: Jorgen Hansen <jhansen@vmware.com>
> >Cc: Norbert Slusarek <nslusarek@gmx.net>
> >Cc: Andra Paraschiv <andraprs@amazon.com>
> >Cc: Colin Ian King <colin.king@canonical.com>
> >Cc: David Brazdil <dbrazdil@google.com>
> >Cc: Alexander Popov <alex.popov@linux.com>
> >Signed-off-by: lixianming <lixianming5@huawei.com>
> >Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
> >---
> > net/vmw_vsock/af_vsock.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index
> >92a72f0..d5df908 100644
> >--- a/net/vmw_vsock/af_vsock.c
> >+++ b/net/vmw_vsock/af_vsock.c
> >@@ -1368,6 +1368,7 @@ static int vsock_stream_connect(struct socket *sock,
> struct sockaddr *addr,
> > lock_sock(sk);
> >
> > if (signal_pending(current)) {
> >+ vsock_send_shutdown(sk, SHUTDOWN_MASK);
>
> I see the issue, but I'm not sure is okay to send the shutdown in any case,
> think about the server didn't setup the connection.
>
> Maybe is better to set TCP_CLOSING if the socket state was TCP_ESTABLISHED,
> so the shutdown will be handled by the
> transport->release() as usual.
>
> What do you think?
>
Your method looks more gracefully, we'll try it and get back to you, thanks.
> Anyway, also without the patch, the server should receive a RST if it
> sends any data to the client, but of course, is better to let it know
> the socket is closed in advance.
>
Yes, agree.
> Thanks,
> Stefano
next prev parent reply other threads:[~2021-05-13 10:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 9:41 [RFC] vsock: notify server to shutdown when client has pending signal Longpeng(Mike)
2021-05-13 9:41 ` Stefano Garzarella
2021-05-13 10:35 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.) [this message]
2021-05-17 2:18 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2021-05-17 10:10 ` Stefano Garzarella
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