Hi On Wed, Jul 27, 2022 at 2:05 PM Bin Meng <bmeng...@gmail.com> wrote:
> On Wed, Jul 27, 2022 at 4:53 PM Konstantin Kostiuk <kkost...@redhat.com> > wrote: > > > > > > > > > > > > On Wed, Jul 27, 2022 at 10:47 AM Bin Meng <bmeng...@gmail.com> wrote: > >> > >> From: Bin Meng <bin.m...@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.ch...@windriver.com> > >> Signed-off-by: Bin Meng <bin.m...@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; > > > > > > I think this is a bad variant to check feature support by checking > > Windows build. From my point, you should try to create an AF_UNIX > > socket and if it fails then fall back to the old behavior. > > > > The caller intends to create an AF_UNIX socket, and if Windows does > not have the capability, it fails, and we return -1 to the caller. > I am not sure what old behavior we should fall back to. > > I agree with Konstantin, we shouldn't check the Windows version, but assume the socket creation can work, and just report a regular error if not. (you can drop some of the preliminary patch then) -- Marc-André Lureau
