Re: [PATCH net-next v2 1/3] vsock: Add support for SIOCINQ ioctl

[Xuewei Niu]

> On Fri, Jun 13, 2025 at 11:11:50AM +0800, Xuewei Niu wrote:
> >This patch adds support for SIOCINQ ioctl, which returns the number of
> >bytes unread in the socket.
> >
> >Signed-off-by: Xuewei Niu <niuxuewei.nxw@xxxxxxxxxxxx>
> >---
> > include/net/af_vsock.h   |  2 ++
> > net/vmw_vsock/af_vsock.c | 22 ++++++++++++++++++++++
> > 2 files changed, 24 insertions(+)
> >
> >diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> >index d56e6e135158..723a886253ba 100644
> >--- a/include/net/af_vsock.h
> >+++ b/include/net/af_vsock.h
> >@@ -171,6 +171,8 @@ struct vsock_transport {
> >
> > 	/* SIOCOUTQ ioctl */
> > 	ssize_t (*unsent_bytes)(struct vsock_sock *vsk);
> >+	/* SIOCINQ ioctl */
> >+	ssize_t (*unread_bytes)(struct vsock_sock *vsk);
> 
> Instead of adding a new callback, can we just use 
> `vsock_stream_has_data()` ?
>
> Maybe adjusting it or changing something in the transports, but for 
> virtio-vsock, it seems to me it does exactly what the new 
> `virtio_transport_unread_bytes()` does, right?

Sorry, I forgot to update this.

I am curious that is there a plan to implement dgram support in
virtio-vsock? If yes, adding a new callback is the right way to go. I
deadly hope to see that feature. If no, will do in the next.

Thanks,
Xuewei

> Thanks,
> Stefano
> 
> >
> > 	/* Shutdown. */
> > 	int (*shutdown)(struct vsock_sock *, int);
> >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> >index 2e7a3034e965..466b1ebadbbc 100644
> >--- a/net/vmw_vsock/af_vsock.c
> >+++ b/net/vmw_vsock/af_vsock.c
> >@@ -1389,6 +1389,28 @@ static int vsock_do_ioctl(struct socket *sock, unsigned int cmd,
> > 	vsk = vsock_sk(sk);
> >
> > 	switch (cmd) {
> >+	case SIOCINQ: {
> >+		ssize_t n_bytes;
> >+
> >+		if (!vsk->transport || !vsk->transport->unread_bytes) {
> >+			ret = -EOPNOTSUPP;
> >+			break;
> >+		}
> >+
> >+		if (sock_type_connectible(sk->sk_type) &&
> >+		    sk->sk_state == TCP_LISTEN) {
> >+			ret = -EINVAL;
> >+			break;
> >+		}
> >+
> >+		n_bytes = vsk->transport->unread_bytes(vsk);
> >+		if (n_bytes < 0) {
> >+			ret = n_bytes;
> >+			break;
> >+		}
> >+		ret = put_user(n_bytes, arg);
> >+		break;
> >+	}
> > 	case SIOCOUTQ: {
> > 		ssize_t n_bytes;
> >
> >-- 
> >2.34.1
> >