Re: [Qemu-devel] [PATCH v2 1/2] io: move fd_is_socket() into common sockets code

[Eric Blake <eblake@redhat.com>]

On 12/21/2017 09:59 AM, Daniel P. Berrange wrote:
> The fd_is_socket() helper method is useful in a few places, so put it in
> the common sockets code.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>   include/qemu/sockets.h |  1 +
>   io/channel-util.c      | 13 -------------
>   util/qemu-sockets.c    | 13 +++++++++++++
>   3 files changed, 14 insertions(+), 13 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

But while you are touching this...

> +++ b/util/qemu-sockets.c
> @@ -91,6 +91,19 @@ NetworkAddressFamily inet_netfamily(int family)
>       return NETWORK_ADDRESS_FAMILY_UNKNOWN;
>   }
>   
> +bool fd_is_socket(int fd)
> +{
> +    int optval;
> +    socklen_t optlen;
> +    optlen = sizeof(optval);
> +    return qemu_getsockopt(fd,
> +                           SOL_SOCKET,
> +                           SO_TYPE,
> +                           (char *)&optval,

This cast is pointless (although you are just moving it from the old 
code).  qemu_getsockopt() already takes care of casting for mingw (where 
the signature is not POSIX-compliant), and on all other platforms, the 
argument is already prototyped as void*; and since void* accepts 
anything, you don't have to go through an intermediate char*.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org