Re: [MASSMAIL KLMS] [virtio-comment] Re: [RFC PATCH v1] virtio-vsock: use enums instead of hardcoded constants

[Arseny Krasnov <arseny.krasnov@kaspersky.com>]

On 16.03.2021 11:19, Stefano Garzarella wrote:
> On Tue, Mar 16, 2021 at 06:35:11AM +0300, Arseny Krasnov wrote:
>> On 15.03.2021 18:53, Cornelia Huck wrote:
>>> On Mon, 15 Mar 2021 11:35:41 +0300
>>> Arseny Krasnov <arseny.krasnov@kaspersky.com> wrote:
>>>
>>>> This replaces constants defined in "bit X set to Y" manner
>>>> with enums from Linux kernel uapi headers.
>>>> ---
>>>>  virtio-vsock.tex | 29 ++++++++++++++++++++++-------
>>>>  1 file changed, 22 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/virtio-vsock.tex b/virtio-vsock.tex
>>>> index da7e641..a97a81e 100644
>>>> --- a/virtio-vsock.tex
>>>> +++ b/virtio-vsock.tex
>>>> @@ -140,8 +140,14 @@ \subsubsection{Addressing}\label{sec:Device Types / Socket Device / Device Opera
>>>>  consists of a (cid, port number) tuple. The header fields used for this are
>>>>  \field{src_cid}, \field{src_port}, \field{dst_cid}, and \field{dst_port}.
>>>>
>>>> -Currently only stream sockets are supported. \field{type} is 1 for stream
>>>> -socket types.
>>>> +Currently only stream sockets are supported. \field{type} is one of the
>>>> +following constants:
>>>> +
>>>> +\begin{lstlisting}
>>>> +enum virtio_vsock_type {
>>>> +	VIRTIO_VSOCK_TYPE_STREAM = 1,
>>>> +};
>>>> +\end{lstlisting}
>>>>
>>>>  Stream sockets provide in-order, guaranteed, connection-oriented delivery
>>>>  without message boundaries.
>>>> @@ -221,11 +227,20 @@ \subsubsection{Stream Sockets}\label{sec:Device Types / Socket Device / Device O
>>>>  a listening socket does not exist on the destination or the destination has
>>>>  insufficient resources to establish the connection.
>>>>
>>>> -When a connected socket receives VIRTIO_VSOCK_OP_SHUTDOWN the header
>>>> -\field{flags} field bit 0 indicates that the peer will not receive any more
>>>> -data and bit 1 indicates that the peer will not send any more data.  These
>>>> -hints are permanent once sent and successive packets with bits clear do not
>>>> -reset them.
>>>> +When a connected socket receives VIRTIO_VSOCK_OP_SHUTDOWN, header \field{flags}
>>>> +field is one of the following constants:
>>> I don't think these two are required to be mutually exclusive (i.e.
>>> both can be indicated at the same time?)
>> I'm not sure, in Linux driver there are several cases when these constants are used
>>
>> independently from each over, but I think, this is question to implementation of virtio
>>
>> vsock protocol, while this patch is cosmetic for specification.
>>
> I think Cornelia's point is that from the "is one of the following 
> constants" sentence it looks like only one of these flags can be set.
> Instead both of them could be set together, and I guess this is the most 
> frequent use case.
>
> Thanks,
> Stefano
Ok, understood.I'll fix it.
>
>>>> +
>>>> +\begin{lstlisting}
>>>> +enum virtio_vsock_shutdown {
>>>> +	VIRTIO_VSOCK_SHUTDOWN_RCV = 1,
>>>> +	VIRTIO_VSOCK_SHUTDOWN_SEND = 2,
>>>> +};
>>>> +\end{lstlisting}
>>>> +
>>>> +VIRTIO_VSOCK_SHUTDOWN_RCV indicates that the peer will not receive any more
>>>> +data and VIRTIO_VSOCK_SHUTDOWN_SEND indicates that the peer will not send
>>>> +any more data.  These hints are permanent once sent and successive packets
>>>> +with bits clear do not reset them.
>>>>
>>>>  The VIRTIO_VSOCK_OP_RST packet aborts the connection process or forcibly
>>>>  disconnects a connected socket.
>>> This publicly archived list offers a means to provide input to the
>>> OASIS Virtual I/O Device (VIRTIO) TC.
>>>
>>> In order to verify user consent to the Feedback License terms and
>>> to minimize spam in the list archive, subscription is required
>>> before posting.
>>>
>>> Subscribe: virtio-comment-subscribe@lists.oasis-open.org
>>> Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org
>>> List help: virtio-comment-help@lists.oasis-open.org
>>> List archive: https://lists.oasis-open.org/archives/virtio-comment/
>>> Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf
>>> List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists
>>> Committee: https://www.oasis-open.org/committees/virtio/
>>> Join OASIS: https://www.oasis-open.org/join/
>>>
>>>
>