From: Stefano Garzarella <sgarzare@redhat.com>
To: Arseny Krasnov <arseny.krasnov@kaspersky.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jorgen Hansen <jhansen@vmware.com>,
Andra Paraschiv <andraprs@amazon.com>,
Colin Ian King <colin.king@canonical.com>,
Norbert Slusarek <nslusarek@gmx.net>,
Alexander Popov <alex.popov@linux.com>,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
stsp2@yandex.ru, oxffffaa@gmail.com
Subject: Re: [RFC PATCH v8 04/19] af_vsock: implement SEQPACKET receive loop
Date: Wed, 21 Apr 2021 10:37:32 +0200 [thread overview]
Message-ID: <20210421083732.hxlilatddifcokjx@steredhat> (raw)
In-Reply-To: <20210413124250.3400313-1-arseny.krasnov@kaspersky.com>
On Tue, Apr 13, 2021 at 03:42:47PM +0300, Arseny Krasnov wrote:
>This adds receive loop for SEQPACKET. It looks like receive loop for
>STREAM, but there is a little bit difference:
>1) It doesn't call notify callbacks.
>2) It doesn't care about 'SO_SNDLOWAT' and 'SO_RCVLOWAT' values, because
> there is no sense for these values in SEQPACKET case.
>3) It waits until whole record is received or error is found during
> receiving.
>4) It processes and sets 'MSG_TRUNC' flag.
>
>So to avoid extra conditions for two types of socket inside one loop, two
>independent functions were created.
>
>Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
>---
>v7 -> v8:
> - Length of message is now not returned by callback, it returns only
> length of data read by each call.
> - Previous case, when EAGAIN is return and dequeue loop restarted now
> removed(in this simplified version we consider that message could not
> be corrupted).
> - MSG_TRUNC in input flags is now handled by callback.
>
> include/net/af_vsock.h | 4 +++
> net/vmw_vsock/af_vsock.c | 66 +++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 69 insertions(+), 1 deletion(-)
>
>diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
>index b1c717286993..5175f5a52ce1 100644
>--- a/include/net/af_vsock.h
>+++ b/include/net/af_vsock.h
>@@ -135,6 +135,10 @@ struct vsock_transport {
> bool (*stream_is_active)(struct vsock_sock *);
> bool (*stream_allow)(u32 cid, u32 port);
>
>+ /* SEQ_PACKET. */
>+ ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
>+ int flags, bool *msg_ready);
>+
> /* Notification. */
> int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
> int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index c4f6bfa1e381..d9fb4f9a3063 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -1974,6 +1974,67 @@ static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
> return err;
> }
>
>+static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
>+ size_t len, int flags)
>+{
>+ const struct vsock_transport *transport;
>+ bool msg_ready;
>+ struct vsock_sock *vsk;
>+ ssize_t record_len;
>+ long timeout;
>+ int err = 0;
>+ DEFINE_WAIT(wait);
>+
>+ vsk = vsock_sk(sk);
>+ transport = vsk->transport;
>+
>+ timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
>+ msg_ready = false;
>+ record_len = 0;
>+
>+ while (1) {
>+ ssize_t tmp_record_len;
Maybe better a name like `partial_len`, `fragment_len`, or just `read`.
>+
>+ if (vsock_wait_data(sk, &wait, timeout, NULL, 0) <= 0) {
>+ /* In case of any loop break(timeout, signal
>+ * interrupt or shutdown), we report user that
>+ * nothing was copied.
>+ */
>+ err = 0;
>+ break;
>+ }
>+
>+ tmp_record_len = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready);
I think we can avoid to pass 'flags' down to the transports.
We can require that seqpacket_dequeue() should always return the real
size of the packet received, and then check below if 'MSG_TRUNC' was
set...
>+
>+ if (tmp_record_len < 0) {
>+ err = -ENOMEM;
>+ break;
>+ }
>+
>+ record_len += tmp_record_len;
>+
>+ if (msg_ready)
>+ break;
>+ }
>+
>+ if (sk->sk_err)
>+ err = -sk->sk_err;
>+ else if (sk->sk_shutdown & RCV_SHUTDOWN)
>+ err = 0;
>+
>+ if (msg_ready && err == 0) {
>+ err = record_len;
>+
>+ /* Always set MSG_TRUNC if real length of packet is
>+ * bigger than user's buffer.
>+ */
...here:
if (flags & MSG_TRUNC && record_len > len)
>+ if (record_len > len)
>+ msg->msg_flags |= MSG_TRUNC;
>+ }
>+
>+ return err;
>+}
>+
> static int
> vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> int flags)
>@@ -2029,7 +2090,10 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> goto out;
> }
>
>- err = __vsock_stream_recvmsg(sk, msg, len, flags);
>+ if (sk->sk_type == SOCK_STREAM)
>+ err = __vsock_stream_recvmsg(sk, msg, len, flags);
>+ else
>+ err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
>
> out:
> release_sock(sk);
>-- )
>2.25.1
>
next prev parent reply other threads:[~2021-04-21 8:37 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 12:39 [RFC PATCH v8 00/19] virtio/vsock: introduce SOCK_SEQPACKET support Arseny Krasnov
2021-04-13 12:41 ` [RFC PATCH v8 01/19] af_vsock: update functions for connectible socket Arseny Krasnov
2021-04-13 12:42 ` [RFC PATCH v8 02/19] af_vsock: separate wait data loop Arseny Krasnov
2021-04-13 12:42 ` [RFC PATCH v8 03/19] af_vsock: separate receive " Arseny Krasnov
2021-04-13 12:42 ` [RFC PATCH v8 04/19] af_vsock: implement SEQPACKET receive loop Arseny Krasnov
2021-04-21 8:37 ` Stefano Garzarella [this message]
2021-04-21 14:47 ` Arseny Krasnov
2021-04-13 12:43 ` [RFC PATCH v8 05/19] af_vsock: implement send logic for SEQPACKET Arseny Krasnov
2021-04-13 12:43 ` [RFC PATCH v8 06/19] af_vsock: rest of SEQPACKET support Arseny Krasnov
2021-04-13 12:43 ` [RFC PATCH v8 07/19] af_vsock: update comments for stream sockets Arseny Krasnov
2021-04-13 12:43 ` [RFC PATCH v8 08/19] virtio/vsock: set packet's type in virtio_transport_send_pkt_info() Arseny Krasnov
2021-04-13 12:44 ` [RFC PATCH v8 09/19] virtio/vsock: simplify credit update function API Arseny Krasnov
2021-04-13 12:44 ` [RFC PATCH v8 10/19] virtio/vsock: defines and constants for SEQPACKET Arseny Krasnov
2021-04-13 12:44 ` [RFC PATCH v8 11/19] virtio/vsock: dequeue callback for SOCK_SEQPACKET Arseny Krasnov
2021-04-14 5:21 ` Arseny Krasnov
2021-04-21 8:56 ` Stefano Garzarella
2021-04-21 14:49 ` Arseny Krasnov
2021-04-13 12:45 ` [RFC PATCH v8 12/19] virtio/vsock: add SEQPACKET receive logic Arseny Krasnov
2021-04-13 12:45 ` [RFC PATCH v8 13/19] virtio/vsock: rest of SOCK_SEQPACKET support Arseny Krasnov
2021-04-21 9:12 ` Stefano Garzarella
2021-04-21 14:50 ` Arseny Krasnov
2021-04-13 12:45 ` [RFC PATCH v8 14/19] virtio/vsock: enable SEQPACKET for transport Arseny Krasnov
2021-04-21 9:22 ` Stefano Garzarella
2021-04-13 12:46 ` [RFC PATCH v8 15/19] vhost/vsock: " Arseny Krasnov
2021-04-21 9:31 ` Stefano Garzarella
2021-04-13 12:46 ` [RFC PATCH v8 16/19] vsock/loopback: " Arseny Krasnov
2021-04-21 9:34 ` Stefano Garzarella
2021-04-13 12:46 ` [RFC PATCH v8 17/19] vsock_test: add SOCK_SEQPACKET tests Arseny Krasnov
2021-04-21 9:35 ` Stefano Garzarella
2021-04-21 15:00 ` Arseny Krasnov
2021-04-13 12:47 ` [RFC PATCH v8 18/19] virtio/vsock: update trace event for SEQPACKET Arseny Krasnov
2021-04-13 12:47 ` [RFC PATCH v8 19/19] af_vsock: serialize writes to shared socket Arseny Krasnov
2021-04-14 10:51 ` Arseny Krasnov
2021-04-21 9:38 ` Stefano Garzarella
2021-04-21 15:02 ` Arseny Krasnov
2021-04-21 9:52 ` [RFC PATCH v8 00/19] virtio/vsock: introduce SOCK_SEQPACKET support Stefano Garzarella
2021-04-21 15:06 ` Arseny Krasnov
2021-04-22 8:46 ` Stefano Garzarella
2021-04-22 9:40 ` Arseny Krasnov
2021-04-22 10:02 ` Stefano Garzarella
2021-04-22 10:29 ` Arseny Krasnov
2021-04-22 10:48 ` Stefano Garzarella
2021-04-22 11:41 ` Arseny Krasnov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210421083732.hxlilatddifcokjx@steredhat \
--to=sgarzare@redhat.com \
--cc=alex.popov@linux.com \
--cc=andraprs@amazon.com \
--cc=arseny.krasnov@kaspersky.com \
--cc=colin.king@canonical.com \
--cc=davem@davemloft.net \
--cc=jasowang@redhat.com \
--cc=jhansen@vmware.com \
--cc=kuba@kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mst@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=nslusarek@gmx.net \
--cc=oxffffaa@gmail.com \
--cc=stefanha@redhat.com \
--cc=stsp2@yandex.ru \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).