Re: [Libguestfs] [PATCH v2 1/2] launch: add internal helper for socket paths creation

Introduce an internal helper to create paths for sockets -- will be useful for changing later the logic for placing sockets. Futhermore, check that the length of sockets won't overflow the buffer for their filenames. --- src/guestfs-internal.h | 1 + src/launch-direct.c | 4 +++- src/launch-libvirt.c | 10 ++++++---- src/launch.c | 17 +++++++++++++++++ 4 files changed, 27 insertions(+), 5 deletions(-) diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h index 5ecd322..bff9f64 100644 --- a/src/guestfs-internal.h +++ b/src/guestfs-internal.h @@ -782,6 +782,7 @@ extern void guestfs_int_launch_send_progress (guestfs_h *g, int perdozen); extern char *guestfs_int_appliance_command_line (guestfs_h *g, const char *appliance_dev, int flags); #define APPLIANCE_COMMAND_LINE_IS_TCG 1 const char *guestfs_int_get_cpu_model (int kvm); +int guestfs_int_create_socketname (guestfs_h *g, const char *filename, char (*sockname)[UNIX_PATH_MAX]); extern void guestfs_int_register_backend (const char *name, const struct backend_ops *); extern int guestfs_int_set_backend (guestfs_h *g, const char *method); diff --git a/src/launch-direct.c b/src/launch-direct.c index b8e453d..a81d4b3 100644 --- a/src/launch-direct.c +++ b/src/launch-direct.c @@ -295,7 +295,9 @@ launch_direct (guestfs_h *g, void *datav, const char *arg) /* Using virtio-serial, we need to create a local Unix domain socket * for qemu to connect to. */ - snprintf (data->guestfsd_sock, sizeof data->guestfsd_sock, "%s/guestfsd.sock", g->tmpdir); + if (guestfs_int_create_socketname (g, "guestfsd.sock", + &data->guestfsd_sock) == -1) + goto cleanup0; daemon_accept_sock = socket (AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); if (daemon_accept_sock == -1) { diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c index 8a5d93e..376bd80 100644 --- a/src/launch-libvirt.c +++ b/src/launch-libvirt.c @@ -395,8 +395,9 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri) /* Using virtio-serial, we need to create a local Unix domain socket * for qemu to connect to. */ - snprintf (data->guestfsd_path, sizeof data->guestfsd_path, - "%s/guestfsd.sock", g->tmpdir); + if (guestfs_int_create_socketname (g, "guestfsd.sock", + &data->guestfsd_path) == -1) + goto cleanup; set_socket_create_context (g); @@ -421,8 +422,9 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri) } /* For the serial console. */ - snprintf (data->console_path, sizeof data->console_path, - "%s/console.sock", g->tmpdir); + if (guestfs_int_create_socketname (g, "console.sock", + &data->console_path) == -1) + goto cleanup; console_sock = socket (AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); if (console_sock == -1) { diff --git a/src/launch.c b/src/launch.c index f59818f..60f02a7 100644 --- a/src/launch.c +++ b/src/launch.c @@ -418,6 +418,23 @@ guestfs_int_get_cpu_model (int kvm) #endif } +/* Create the path for a socket with the selected filename in the + * tmpdir. + */ +int +guestfs_int_create_socketname (guestfs_h *g, const char *filename, + char (*sockpath)[UNIX_PATH_MAX]) +{ + if (strlen (g->tmpdir) + 1 + strlen (filename) > UNIX_PATH_MAX-1) { + error (g, _("socket path too long: %s/%s"), g->tmpdir, filename); + return -1; + } + + snprintf (*sockpath, UNIX_PATH_MAX, "%s/%s", g->tmpdir, filename); + + return 0; +} + /* glibc documents, but does not actually implement, a 'getumask(3)' * call. This implements a thread-safe way to get the umask. Note * this is only called when g->verbose is true and after g->tmpdir