Re: [PATCH 2/5] 9pfs: fix qemu_mknodat(S_IFSOCK) on macOS

[Christian Schoenebeck]

On Mittwoch, 20. April 2022 14:10:44 CEST Greg Kurz wrote:
> On Tue, 19 Apr 2022 13:41:03 +0200
> 
> Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > mknod() on macOS does not support creating sockets, so divert to
> > call sequence socket(), bind() and chmod() respectively if S_IFSOCK
> > was passed with mode argument.
> > 
> > Link: https://lore.kernel.org/qemu-devel/17933734.zYzKuhC07K@silver/
> > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > ---
> > 
> >  hw/9pfs/9p-util-darwin.c | 24 +++++++++++++++++++++++-
> >  1 file changed, 23 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/9pfs/9p-util-darwin.c b/hw/9pfs/9p-util-darwin.c
> > index 53e0625501..252a6fc5dd 100644
> > --- a/hw/9pfs/9p-util-darwin.c
> > +++ b/hw/9pfs/9p-util-darwin.c
> > @@ -74,6 +74,24 @@ int fsetxattrat_nofollow(int dirfd, const char
> > *filename, const char *name,> 
> >   */
> >  
> >  #if defined CONFIG_PTHREAD_FCHDIR_NP
> > 
> > +static int create_socket_file_at_cwd(const char *filename, mode_t mode) {
> > +    int fd, err;
> > +    struct sockaddr_un addr = {
> > +        .sun_family = AF_UNIX
> > +    };
> > +
> > +    fd = socket(PF_UNIX, SOCK_DGRAM, 0);
> > +    if (fd < 0) {
> > +        return fd;
> > +    }
> > +    snprintf(addr.sun_path, sizeof(addr.sun_path), "./%s", filename);
> > +    err = bind(fd, (struct sockaddr *) &addr, sizeof(addr));
> > +    if (err < 0) {
> > +        return err;
> > +    }
> > +    return chmod(addr.sun_path, mode);
> 
> As with the other patch, you should close() the socket.

I was concerned that close(fd) might cause the socket file to disappear. But I 
just tested this now on macOS and it works fine. So will be fixed in v2.

Thanks!

Best regards,
Christian Schoenebeck