Commit a75f501d authored by Arseniy Krasnov's avatar Arseniy Krasnov Committed by Paolo Abeni
Browse files

virtio/vsock: support MSG_PEEK for SOCK_SEQPACKET 



This adds support of MSG_PEEK flag for SOCK_SEQPACKET type of socket.
Difference with SOCK_STREAM is that this callback returns either length
of the message or error.

Signed-off-by: default avatarArseniy Krasnov <AVKrasnov@sberdevices.ru>
Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 051e77e3

net/vmw_vsock/virtio_transport_common.c

+60 −3
Original line number Diff line number Diff line
@@ -460,6 +460,63 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, 
	return err;

}



static ssize_t

virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,

				   struct msghdr *msg)

{

	struct virtio_vsock_sock *vvs = vsk->trans;

	struct sk_buff *skb;

	size_t total, len;



	spin_lock_bh(&vvs->rx_lock);



	if (!vvs->msg_count) {

		spin_unlock_bh(&vvs->rx_lock);

		return 0;

	}



	total = 0;

	len = msg_data_left(msg);



	skb_queue_walk(&vvs->rx_queue, skb) {

		struct virtio_vsock_hdr *hdr;



		if (total < len) {

			size_t bytes;

			int err;



			bytes = len - total;

			if (bytes > skb->len)

				bytes = skb->len;



			spin_unlock_bh(&vvs->rx_lock);



			/* sk_lock is held by caller so no one else can dequeue.

			 * Unlock rx_lock since memcpy_to_msg() may sleep.

			 */

			err = memcpy_to_msg(msg, skb->data, bytes);

			if (err)

				return err;



			spin_lock_bh(&vvs->rx_lock);

		}



		total += skb->len;

		hdr = virtio_vsock_hdr(skb);



		if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {

			if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)

				msg->msg_flags |= MSG_EOR;



			break;

		}

	}



	spin_unlock_bh(&vvs->rx_lock);



	return total;

}



static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,

						 struct msghdr *msg,

						 int flags)
@@ -554,8 +611,8 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, 
				   int flags)

{

	if (flags & MSG_PEEK)

		return -EOPNOTSUPP;



		return virtio_transport_seqpacket_do_peek(vsk, msg);

	else

		return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);

}

EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);