Re: [PATCH 08/10] qmp: add 'get-win32-socket'

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Jan 03, 2023 at 03:08:12PM +0400, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> A process with enough capabilities can duplicate a socket to QEMU. Add a
> QMP command to import it and add it to the monitor fd list, so it can be
> later used by other commands.
> 
> Note that we actually store the SOCKET in the FD list, appropriate care
> must now be taken to use the correct socket functions (similar approach
> is taken by our io/ code and in glib, this is internal and shouldn't
> affect the QEMU/QMP users)
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  qapi/misc.json | 32 ++++++++++++++++++++++
>  monitor/misc.c | 74 ++++++++++++++++++++++++++++++++++++++++----------
>  2 files changed, 91 insertions(+), 15 deletions(-)
> 
> diff --git a/qapi/misc.json b/qapi/misc.json
> index 27ef5a2b20..a19dd78fab 100644
> --- a/qapi/misc.json
> +++ b/qapi/misc.json
> @@ -272,6 +272,38 @@
>  ##
>  { 'command': 'getfd', 'data': {'fdname': 'str'} }
>  
> +##
> +# @get-win32-socket:
> +#
> +# Add a socket that was duplicated to QEMU process with WSADuplicateSocketW()
> +# via WSASocket() & WSAPROTOCOL_INFOW structure and assign it a name. A SOCKET
> +# is considered as a kind of "file descriptor" by QMP clients, for historical
> +# reasons and simplicity, although QEMU takes care to use socket functions
> +# appropriately.
> +#
> +# @info: the WSAPROTOCOL_INFOW structure (encoded in base64)
> +#
> +# @fdname: file descriptor name
> +#
> +# Returns: Nothing on success
> +#
> +# Since: 8.0
> +#
> +# Notes: If @fdname already exists, the file descriptor assigned to
> +#        it will be closed and replaced by the received file
> +#        descriptor.
> +#
> +#        The 'closefd' command can be used to explicitly close the
> +#        file descriptor when it is no longer needed.
> +#
> +# Example:
> +#
> +# -> { "execute": "get-win32-socket", "arguments": { "info": "abcd123..", fdname": "skclient" } }
> +# <- { "return": {} }
> +#
> +##
> +{ 'command': 'get-win32-socket', 'data': {'info': 'str', 'fdname': 'str'}, 'if': 'CONFIG_WIN32' }

IIUC, this is needed because  'getfd' doesn't work on Windows ?

Can't we just implement getfd on Windows, using this WSAPROTOCOL_INFOW
structure passing, or are you anticipating that future Windows make get
normal 'getfd' support ?  

With regards,
Daniel
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