Re: [PATCH] tools/xenstore: rework path length check

[Wei Liu <wl@xxxxxxx>]

On Tue, Dec 15, 2020 at 04:04:11PM +0100, Juergen Gross wrote:
> The different fixed limits for absolute and relative path lengths of
> Xenstore nodes make it possible to create per-domain nodes via
> absolute paths which are not accessible using relative paths, as the
> two limits differ by 1024 characters.
> 
> Instead of this weird limits use only one limit, which applies to the
> relative path length of per-domain nodes and to the absolute path
> length of all other nodes. This means, the path length check is
> applied to the path after removing a possible start of
> "/local/domain/<n>/" with <n> being a domain id.
> 
> There has been the request to be able to limit the path lengths even
> more, so an additional quota is added which can be applied to path
> lengths. It is XENSTORE_REL_PATH_MAX (2048) per default, but can be
> set to lower values. This is done via the new "-M" or "--path-max"
> option when invoking xenstored.
> 
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> Reviewed-by: Paul Durrant <paul@xxxxxxx>
> Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

Acked-by: Wei Liu <wl@xxxxxxx>