Re: [Libguestfs] [PATCH] lib: Better handling for problems creating the socket path

GCC 12 gives a warning about our previous attempt to check the length of the socket path. In the ensuing discussion it was pointed out that it is easier to get snprintf to do the hard work. snprintf will return an int >= UNIX_PATH_MAX if the path is too long, or -1 if there are other errors such as locale/encoding problems. So we should just check for those two cases instead. https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.o... Thanks: Martin Sebor and Laszlo Ersek --- lib/launch.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/lib/launch.c b/lib/launch.c index 253189b200..e3f64aec90 100644 --- a/lib/launch.c +++ b/lib/launch.c @@ -325,15 +325,20 @@ int guestfs_int_create_socketname (guestfs_h *g, const char *filename, char (*sockpath)[UNIX_PATH_MAX]) { + int r; + if (guestfs_int_lazy_make_sockdir (g) == -1) return -1; - if (strlen (g->sockdir) + 1 + strlen (filename) > UNIX_PATH_MAX-1) { + r = snprintf (*sockpath, UNIX_PATH_MAX, "%s/%s", g->sockdir, filename); + if (r >= UNIX_PATH_MAX) { error (g, _("socket path too long: %s/%s"), g->sockdir, filename); return -1; } - - snprintf (*sockpath, UNIX_PATH_MAX, "%s/%s", g->sockdir, filename); + if (r == -1) { + perrorf (g, _("%s"), g->sockdir); + return -1; + } return 0; }