[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [Libguestfs] [xml] Why does libxml2 limit port numbers to 999, 999, 999?



On Sat, Oct 17, 2020 at 06:32:18PM +0200, Nick Wellnhofer wrote:
> On Oct 17, 2020, at 12:24 , Richard W.M. Jones via xml <xml gnome org> wrote:
> > It seems like libxml2 chose to do this for convenience rather than
> > correctness.
> 
> Yes, this is an arbitrary limit introduced to avoid integer overflow.
>  
> > I think it should accept port numbers at least up to
> > signed int (the type used to store port numbers), and give an error if
> > the port number overflows.
> 
> This is fixed now: https://gitlab.gnome.org/GNOME/libxml2/-/commit/b46016b8705b041c0678dd45e445dc73674b75d0

Oh that's great thanks.  Can confirm it works for me (up to INT_MAX).

> > Also could the uri->port field be changed to unsigned int without
> > breaking ABI?
>
> It’s a public struct member, so strictly speaking, no. But the risk
> to break stuff seems low.

This would allow us to go to 2^32-1 which is the full range of
port numbers for AF_VSOCK.

** Stefano ** Do you think this is worth it for the vsock protocol?
I'm not sure how often huge port numbers are used - I only hit this
bug because I was choosing random port numbers in a test case.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://libguestfs.org


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]