iproute2: support dotted-quad netmask notation.

iproute2: support dotted-quad netmask notation.

On tor, 2007-12-06 at 11:53 -0800, Stephen Hemminger wrote:
> On Tue, 4 Dec 2007 14:58:18 +0100
> Andreas Henriksson <andreas@fatal.se> wrote:
>
> > Suggested patch for allowing netmask to be specified in dotted quad format.
> > See http://bugs.debian.org/357172
> >
> > (Known problem: this will not prevent some invalid syntaxes,
> > ie. "255.0.255.0" will be treated as "255.255.255.0")
> >
> > Comments? Suggestions? Improvements?
>
> Fix the bug you mentioned?
>
> [... snip example code ...]

Updated patch, added your netmask validation code but without the check
that made 0.0.0.0 (default) and 255.255.255.255 (one address) invalid
netmasks as they are permitted in CIDR format.

Signed-off-by: Andreas Henriksson <andreas@fatal.se>
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>