Hi On Thu, Mar 12, 2020 at 11:49 AM Daniel P. Berrangé <berra...@redhat.com> wrote: > > On Thu, Mar 12, 2020 at 10:41:42AM +0000, Alex Bennée wrote: > > If you like running QEMU as a normal user (very common for TCG runs) > > but you have to run virtiofsd as a root user you run into connection > > problems. Adding support for an optional --socket-group allows the > > users to keep using the command line. > > If we're going to support this, then I think we need to put it in > the vhost-user.rst specification so we standardize across backends. > >
Perhaps. Otoh, I wonder if the backend spec should be more limited to arguments/introspection that are used by programs. In this case, I even consider --socket-path to be unnecessary, as a management layer can/should provide a preopened & setup fd directly. What do you think? > > > Signed-off-by: Alex Bennée <alex.ben...@linaro.org> > > > > > > --- > > v1 > > - tweak documentation and commentary > > --- > > docs/tools/virtiofsd.rst | 4 ++++ > > tools/virtiofsd/fuse_i.h | 1 + > > tools/virtiofsd/fuse_lowlevel.c | 6 ++++++ > > tools/virtiofsd/fuse_virtio.c | 20 ++++++++++++++++++-- > > 4 files changed, 29 insertions(+), 2 deletions(-) > > > > diff --git a/docs/tools/virtiofsd.rst b/docs/tools/virtiofsd.rst > > index 378594c422a..5a8246b74f8 100644 > > --- a/docs/tools/virtiofsd.rst > > +++ b/docs/tools/virtiofsd.rst > > @@ -85,6 +85,10 @@ Options > > > > Listen on vhost-user UNIX domain socket at PATH. > > > > +.. option:: --socket-group=GROUP > > + > > + Set the vhost-user UNIX domain socket gid to GROUP. > > + > > .. option:: --fd=FDNUM > > > > Accept connections from vhost-user UNIX domain socket file descriptor > > FDNUM. > > diff --git a/tools/virtiofsd/fuse_i.h b/tools/virtiofsd/fuse_i.h > > index 1240828208a..492e002181e 100644 > > --- a/tools/virtiofsd/fuse_i.h > > +++ b/tools/virtiofsd/fuse_i.h > > @@ -68,6 +68,7 @@ struct fuse_session { > > size_t bufsize; > > int error; > > char *vu_socket_path; > > + char *vu_socket_group; > > int vu_listen_fd; > > int vu_socketfd; > > struct fv_VuDev *virtio_dev; > > diff --git a/tools/virtiofsd/fuse_lowlevel.c > > b/tools/virtiofsd/fuse_lowlevel.c > > index 2dd36ec03b6..4d1ba2925d1 100644 > > --- a/tools/virtiofsd/fuse_lowlevel.c > > +++ b/tools/virtiofsd/fuse_lowlevel.c > > @@ -2523,6 +2523,7 @@ static const struct fuse_opt fuse_ll_opts[] = { > > LL_OPTION("--debug", debug, 1), > > LL_OPTION("allow_root", deny_others, 1), > > LL_OPTION("--socket-path=%s", vu_socket_path, 0), > > + LL_OPTION("--socket-group=%s", vu_socket_group, 0), > > LL_OPTION("--fd=%d", vu_listen_fd, 0), > > LL_OPTION("--thread-pool-size=%d", thread_pool_size, 0), > > FUSE_OPT_END > > @@ -2630,6 +2631,11 @@ struct fuse_session *fuse_session_new(struct > > fuse_args *args, > > "fuse: --socket-path and --fd cannot be given > > together\n"); > > goto out4; > > } > > + if (se->vu_socket_group && !se->vu_socket_path) { > > + fuse_log(FUSE_LOG_ERR, > > + "fuse: --socket-group can only be used with > > --socket-path\n"); > > + goto out4; > > + } > > > > se->bufsize = FUSE_MAX_MAX_PAGES * getpagesize() + > > FUSE_BUFFER_HEADER_SIZE; > > > > diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c > > index 3b6d16a0417..331f9fc65c5 100644 > > --- a/tools/virtiofsd/fuse_virtio.c > > +++ b/tools/virtiofsd/fuse_virtio.c > > @@ -31,6 +31,8 @@ > > #include <sys/socket.h> > > #include <sys/types.h> > > #include <sys/un.h> > > +#include <sys/types.h> > > +#include <grp.h> > > #include <unistd.h> > > > > #include "contrib/libvhost-user/libvhost-user.h" > > @@ -924,15 +926,29 @@ static int fv_create_listen_socket(struct > > fuse_session *se) > > > > /* > > * Unfortunately bind doesn't let you set the mask on the socket, > > - * so set umask to 077 and restore it later. > > + * so set umask appropriately and restore it later. > > */ > > - old_umask = umask(0077); > > + if (se->vu_socket_group) { > > + old_umask = umask(S_IROTH | S_IWOTH | S_IXOTH); > > + } else { > > + old_umask = umask(S_IRGRP | S_IWGRP | S_IXGRP | S_IROTH | S_IWOTH > > | S_IXOTH); > > + } > > if (bind(listen_sock, (struct sockaddr *)&un, addr_len) == -1) { > > fuse_log(FUSE_LOG_ERR, "vhost socket bind: %m\n"); > > close(listen_sock); > > umask(old_umask); > > return -1; > > } > > + if (se->vu_socket_group) { > > + struct group *g = getgrnam(se->vu_socket_group); > > + if (g) { > > + if (!chown(se->vu_socket_path, -1, g->gr_gid)) { > > + fuse_log(FUSE_LOG_WARNING, > > + "vhost socket failed to set group to %s (%d)\n", > > + se->vu_socket_group, g->gr_gid); > > + } > > + } > > + } > > umask(old_umask); > > > > if (listen(listen_sock, 1) == -1) { > > -- > > 2.20.1 > > > > > > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| > > -- Marc-André Lureau