virtio/vsock: enable SEQPACKET for transport

To make transport work with SOCK_SEQPACKET add two things:
1) SOCK_SEQPACKET ops for virtio transport and 'seqpacket_allow()'
   callback.
2) Handling of SEQPACKET bit: guest tries to negotiate it with vhost,
   so feature will be enabled only if bit is negotiated with device.

Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 2700a63..e73ce65 100644 (file)
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -62,6 +62,7 @@ struct virtio_vsock {
        struct virtio_vsock_event event_list[8];
 
        u32 guest_cid;
+       bool seqpacket_allow;
 };
 
 static u32 virtio_transport_get_local_cid(void)
@@ -443,6 +444,8 @@ static void virtio_vsock_rx_done(struct virtqueue *vq)
        queue_work(virtio_vsock_workqueue, &vsock->rx_work);
 }
 
+static bool virtio_transport_seqpacket_allow(u32 remote_cid);
+
 static struct virtio_transport virtio_transport = {
        .transport = {
                .module                   = THIS_MODULE,
@@ -469,6 +472,11 @@ static struct virtio_transport virtio_transport = {
                .stream_is_active         = virtio_transport_stream_is_active,
                .stream_allow             = virtio_transport_stream_allow,
 
+               .seqpacket_dequeue        = virtio_transport_seqpacket_dequeue,
+               .seqpacket_enqueue        = virtio_transport_seqpacket_enqueue,
+               .seqpacket_allow          = virtio_transport_seqpacket_allow,
+               .seqpacket_has_data       = virtio_transport_seqpacket_has_data,
+
                .notify_poll_in           = virtio_transport_notify_poll_in,
                .notify_poll_out          = virtio_transport_notify_poll_out,
                .notify_recv_init         = virtio_transport_notify_recv_init,
@@ -485,6 +493,19 @@ static struct virtio_transport virtio_transport = {
        .send_pkt = virtio_transport_send_pkt,
 };
 
+static bool virtio_transport_seqpacket_allow(u32 remote_cid)
+{
+       struct virtio_vsock *vsock;
+       bool seqpacket_allow;
+
+       rcu_read_lock();
+       vsock = rcu_dereference(the_virtio_vsock);
+       seqpacket_allow = vsock->seqpacket_allow;
+       rcu_read_unlock();
+
+       return seqpacket_allow;
+}
+
 static void virtio_transport_rx_work(struct work_struct *work)
 {
        struct virtio_vsock *vsock =
@@ -608,10 +629,14 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
        vsock->event_run = true;
        mutex_unlock(&vsock->event_lock);
 
+       if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET))
+               vsock->seqpacket_allow = true;
+
        vdev->priv = vsock;
        rcu_assign_pointer(the_virtio_vsock, vsock);
 
        mutex_unlock(&the_virtio_vsock_mutex);
+
        return 0;
 
 out:
@@ -695,6 +720,7 @@ static struct virtio_device_id id_table[] = {
 };
 
 static unsigned int features[] = {
+       VIRTIO_VSOCK_F_SEQPACKET
 };
 
 static struct virtio_driver virtio_vsock_driver = {