On Tuesday, September 13, 2016 5:13:10 AM CEST Matthew White wrote: > On Mon, 12 Sep 2016 21:20:54 +0200 > > Tim Rühsen <[email protected]> wrote: > > On Montag, 12. September 2016 20:18:30 CEST Eli Zaretskii wrote: > > > > From: Tim Ruehsen <[email protected]> > > > > Date: Mon, 12 Sep 2016 13:00:32 +0200 > > > > > > > > > + char *basename = name; > > > > > + > > > > > + while ((name = strstr (basename, "/"))) > > > > > + basename = name + 1; > > > > > > > > Could you use strrchr() ? something like > > > > > > > > char *basename = strrchr (name, '/'); > > > > > > > > if (basename) > > > > > > > > basename += 1; > > > > > > > > else > > > > > > > > basename = name; > > > > > > I think we want to use ISSEP, no? Otherwise Windows file names with > > > backslashes will misfire. > > > > Good point. What about device names ? > > > > So maybe base_name() from Gnulib module 'dirname' is the right choice !? > > See https://www.gnu.org/software/gnulib/manual/html_node/basename.html > > What if Gnulib's base_name() returns "./<basename>"? > > libmetalink's metalink_check_safe_path() rejects relative paths: > https://tools.ietf.org/html/rfc5854#section-4.1.2.1 > > Also, basename is used to point to an existing memory location, base_name() > instead allocates new space. This is not a biggy, but we should keep it in > mind to amend properly. > > lib/basename.c (base_name) > -------------------------- > /* On systems with drive letters, "a/b:c" must return "./b:c" rather > than "b:c" to avoid confusion with a drive letter. On systems > with pure POSIX semantics, this is not an issue. */ > -------------------------- > > Suggestions?
ISSEP is "homebrewed" and incomplete but doesn't need a memory allocation. base_name() is "complete" (the macros check more than just WINDOWS) and we automatically get improvements from upstream - but it calls malloc(). There is also last_component() which returns a pointer to the basename within your filename. This is basically what you do. Anyways, this last component (basename) may still hold a device prefix - you have to check that with either HAS_DEVICE() (only defined in certain environments, needs to guarded by #ifdef) or by FILE_SYSTEM_PREFIX_LEN() which gives 2 if your basename has a leading device prefix. And you should do this check in a loop to catch names like 'C:D:xxx'. If you don't do, we likely get a CVE assigned ;-) Regards, Tim
signature.asc
Description: This is a digitally signed message part.
