[PATCH net] VSOCK: handle VIRTIO_VSOCK_OP_CREDIT_REQUEST

[Harshavardhan Unnibhavi <harshanavkis@gmail.com>]

The original implementation of the virtio-vsock driver does not
handle a VIRTIO_VSOCK_OP_CREDIT_REQUEST as required by the
virtio-vsock specification. The vsock device emulated by
vhost-vsock and the virtio-vsock driver never uses this request,
which was probably why nobody noticed it. However, another
implementation of the device may use this request type.

Hence, this commit introduces a way to handle an explicit credit
request by responding with a corresponding credit update as
required by the virtio-vsock specification.

Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko")

Signed-off-by: Harshavardhan Unnibhavi <harshanavkis@gmail.com>
---
 net/vmw_vsock/virtio_transport_common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 169ba8b72a63..081e7ae93cb1 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1079,6 +1079,9 @@ virtio_transport_recv_connected(struct sock *sk,
 		virtio_transport_recv_enqueue(vsk, pkt);
 		sk->sk_data_ready(sk);
 		return err;
+	case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
+		virtio_transport_send_credit_update(vsk);
+		break;
 	case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 		sk->sk_write_space(sk);
 		break;
-- 
2.17.1