Re: [PATCH 4/5] util/qemu-sockets: Enable unix socket support on Windows

[Bin Meng]

On Wed, Jul 27, 2022 at 4:51 PM Yan Vugenfirer <yvugenfi@redhat.com> wrote:
>
> On Wed, Jul 27, 2022 at 10:46 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> >
> > From: Bin Meng <bin.meng@windriver.com>
> >
> > Support for the unix socket has existed both in BSD and Linux for the
> > longest time, but not on Windows. Since Windows 10 build 17063 [1],
> > the native support for the unix socket has came to Windows. Starting
> > this build, two Win32 processes can use the AF_UNIX address family
> > over Winsock API to communicate with each other.
> >
> > Introduce a new build time config option CONFIG_AF_UNIX when the build
> > host has such a capability, and a run-time check afunix_available() for
> > Windows host in the QEMU sockets util codes.
> >
> > [1] https://devblogs.microsoft.com/commandline/af_unix-comes-to-windows/
> >
> > Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
> > Signed-off-by: Bin Meng <bin.meng@windriver.com>
> > ---
> >
> >  meson.build         |  6 ++++++
> >  util/qemu-sockets.c | 48 ++++++++++++++++++++++++++++++++++++++-------
> >  2 files changed, 47 insertions(+), 7 deletions(-)
> >
> > diff --git a/meson.build b/meson.build
> > index 75aaca8462..73e5de5957 100644
> > --- a/meson.build
> > +++ b/meson.build
> > @@ -2327,6 +2327,12 @@ have_afalg = get_option('crypto_afalg') \
> >    '''), error_message: 'AF_ALG requested but could not be 
> > detected').allowed()
> >  config_host_data.set('CONFIG_AF_ALG', have_afalg)
> >
> > +if targetos != 'windows'
> > +  config_host_data.set('CONFIG_AF_UNIX', true)
> > +else
> > +  config_host_data.set('CONFIG_AF_UNIX', cc.has_header('afunix.h'))
> > +endif
> > +
> >  config_host_data.set('CONFIG_AF_VSOCK', cc.has_header_symbol(
> >    'linux/vm_sockets.h', 'AF_VSOCK',
> >    prefix: '#include <sys/socket.h>',
> > diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
> > index 0e2298278f..d85f3ea3ee 100644
> > --- a/util/qemu-sockets.c
> > +++ b/util/qemu-sockets.c
> > @@ -17,6 +17,15 @@
> >   */
> >  #include "qemu/osdep.h"
> >
> > +#if defined(CONFIG_WIN32) && defined(CONFIG_AF_UNIX)
> > +# include <afunix.h>
> > +/*
> > + * AF_UNIX support is available since Windows 10 build 17063
> > + * See https://devblogs.microsoft.com/commandline/af_unix-comes-to-windows/
> > + */
> > +# define WIN_BUILD_AF_UNIX 17063
> > +#endif /* CONFIG_WIN32 && CONFIG_AF_UNIX */
> > +
> >  #ifdef CONFIG_AF_VSOCK
> >  #include <linux/vm_sockets.h>
> >  #endif /* CONFIG_AF_VSOCK */
> > @@ -880,7 +889,7 @@ static int vsock_parse(VsockSocketAddress *addr, const 
> > char *str,
> >  }
> >  #endif /* CONFIG_AF_VSOCK */
> >
> > -#ifndef _WIN32
> > +#ifdef CONFIG_AF_UNIX
> >
> >  static bool saddr_is_abstract(UnixSocketAddress *saddr)
> >  {
> > @@ -900,6 +909,17 @@ static bool saddr_is_tight(UnixSocketAddress *saddr)
> >  #endif
> >  }
> >
> > +#ifdef CONFIG_WIN32
> > +static bool afunix_available(void)
> > +{
> > +    OSVERSIONINFOEXW os_version = { 0 };
> > +
> > +    os_get_win_version(&os_version);
> > +
> > +    return os_version.dwBuildNumber >= WIN_BUILD_AF_UNIX;
> It can be that CONFIG_WIN32 is defined,but CONFIG_AF_UNIX is not. In
> this case WIN_BUILD_AF_UNIX will be undefined.
> Also, WIN_BUILD_AF_UNIX is just a build constant, why not define it
> always under CONFIG_WIN32?
>

Thanks for the review.

Will put WIN_BUILD_AF_UNIX under CONFIG_WIN32 only.

Regards,
Bin