Re: [Qemu-devel] Make 9pfs buildable for Windows

[Michael Fritscher]

>
> Hi,
>
> dumb question: what is the advantage of openat vs. open - only the thing
> that someone doesn't need to build the path together by hand?
>
> If I understand the man page of openat correctly, it does _not_ prevent
> someone to break out of the jail by using e.g. ../../../blah .
> If this assumption is correctly perhaps it is better to avoid using the
> *at function family (as it was some time ago) and sanitize the path (by
> somehow canonizing it and than check if the beginning is ok).
>
> Then I could use the "normal" posix function again and avoid using the NT*
> Functions directly which is not soooo nice for various reasons.
>
> Best regards,
> Michael Fritscher
>

Hi again,

I see one thing: symlinks somewhere in the path (which seemed to be the
reason introducing the *at family). But I think that this can be handled
by canonlizing the path, too. realpath should do the job quite well.

Best regards,
Michael Fritscher