Libguestfs - Oct 2015 - Re: [PATCH 2/2] actions: turn some params into RelativePathnameList (RHBZ#1174551).

On Tue, Oct 20, 2015 at 01:59:10PM +0200, Pino Toscano
wrote:
> Use RelativePathnameList as type for lists of relative paths, as used in
> some listing-alike APIs.  This way we can ensure absolute paths in those
> lists are rejects outright.
> 
> As a consequence, test-big-dirs.pl does not need to prepend the
> directory name anymore before calling listing-alike APIs: previously
> they didn't fail, but the returned lists contained only invalid
> elements (and only their size was checked).
Are these all relative pathnames, or are they in fact just filenames
without any path at all.  That is to say: is "foo/bar" permitted, or
just "bar"?

Rich.


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On Tuesday 20 October 2015 14:43:53 Richard W.M. Jones
wrote:
> On Tue, Oct 20, 2015 at 01:59:10PM +0200, Pino Toscano wrote:
> > Use RelativePathnameList as type for lists of relative paths, as used
in
> > some listing-alike APIs.  This way we can ensure absolute paths in
those
> > lists are rejects outright.
> > 
> > As a consequence, test-big-dirs.pl does not need to prepend the
> > directory name anymore before calling listing-alike APIs: previously
> > they didn't fail, but the returned lists contained only invalid
> > elements (and only their size was checked).
> 
> Are these all relative pathnames, or are they in fact just filenames
> without any path at all.  That is to say: is "foo/bar" permitted,
or
> just "bar"?
At least with *lstat*list and *readlinklist functions, the file names
are considered as relative wrt the path specified, as they are resolved
against the file descriptor of the directory.

In case of *lxattrlist, the absolute path+name for each is built and
used as path within the guest.

So yes, "bar", "foo/bar", and "../bar" too, should
work.

-- 
Pino Toscano

On Tue, Oct 20, 2015 at 03:50:31PM +0200, Pino Toscano
wrote:
> On Tuesday 20 October 2015 14:43:53 Richard W.M. Jones wrote:
> > On Tue, Oct 20, 2015 at 01:59:10PM +0200, Pino Toscano wrote:
> > > Use RelativePathnameList as type for lists of relative paths, as
used in
> > > some listing-alike APIs.  This way we can ensure absolute paths
in those
> > > lists are rejects outright.
> > > 
> > > As a consequence, test-big-dirs.pl does not need to prepend the
> > > directory name anymore before calling listing-alike APIs:
previously
> > > they didn't fail, but the returned lists contained only
invalid
> > > elements (and only their size was checked).
> > 
> > Are these all relative pathnames, or are they in fact just filenames
> > without any path at all.  That is to say: is "foo/bar"
permitted, or
> > just "bar"?
> 
> At least with *lstat*list and *readlinklist functions, the file names
> are considered as relative wrt the path specified, as they are resolved
> against the file descriptor of the directory.
> 
> In case of *lxattrlist, the absolute path+name for each is built and
> used as path within the guest.
> 
> So yes, "bar", "foo/bar", and "../bar" too,
should work.
I think I really meant -- is it a caller bug if the parameter contains
a slash in it?

All the *list functions were really intended as optimizations for
fuse/guestmount, and IIRC it was intended that only filenames (not
even relative paths) be used there.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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