[RFC PATCH v9 05/19] af_vsock: implement send logic for SEQPACKET

From: Arseny Krasnov <arseny.krasnov@kaspersky.com>
To: Stefan Hajnoczi <stefanha@redhat.com>,
	Stefano Garzarella <sgarzare@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Arseny Krasnov <arseny.krasnov@kaspersky.com>,
	Jorgen Hansen <jhansen@vmware.com>,
	Norbert Slusarek <nslusarek@gmx.net>,
	Colin Ian King <colin.king@canonical.com>,
	Andra Paraschiv <andraprs@amazon.com>
Cc: <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: [RFC PATCH v9 05/19] af_vsock: implement send logic for SEQPACKET
Date: Sat, 8 May 2021 19:33:28 +0300	[thread overview]
Message-ID: <20210508163332.3431236-1-arseny.krasnov@kaspersky.com> (raw)
In-Reply-To: <20210508163027.3430238-1-arseny.krasnov@kaspersky.com>

This adds some logic to current stream enqueue function for SEQPACKET
support:
1) Use transport's seqpacket enqueue callback.
2) Return value from enqueue function is whole record length or error
   for SOCK_SEQPACKET.

Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
---
 include/net/af_vsock.h   |  2 ++
 net/vmw_vsock/af_vsock.c | 20 +++++++++++++++-----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 5175f5a52ce1..5860027d5173 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -138,6 +138,8 @@ struct vsock_transport {
 	/* SEQ_PACKET. */
 	ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
 				     int flags, bool *msg_ready);
+	int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
+				 size_t len);
 
 	/* Notification. */
 	int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 78b9af545ca8..3f9cfcce1e42 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1808,9 +1808,13 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
 		 * responsibility to check how many bytes we were able to send.
 		 */
 
-		written = transport->stream_enqueue(
-				vsk, msg,
-				len - total_written);
+		if (sk->sk_type == SOCK_SEQPACKET) {
+			written = transport->seqpacket_enqueue(vsk,
+						msg, len - total_written);
+		} else {
+			written = transport->stream_enqueue(vsk,
+					msg, len - total_written);
+		}
 		if (written < 0) {
 			err = -ENOMEM;
 			goto out_err;
@@ -1826,8 +1830,14 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
 	}
 
 out_err:
-	if (total_written > 0)
-		err = total_written;
+	if (total_written > 0) {
+		/* Return number of written bytes only if:
+		 * 1) SOCK_STREAM socket.
+		 * 2) SOCK_SEQPACKET socket when whole buffer is sent.
+		 */
+		if (sk->sk_type == SOCK_STREAM || total_written == len)
+			err = total_written;
+	}
 out:
 	release_sock(sk);
 	return err;
-- 
2.25.1

