New feature: restrict address/cidr

[Achim Gratz]

Am 10.06.2017 um 04:59 schrieb Gary E. Miller via devel:
>> Slightly strange example.  I'd expect 10.0.0.0 mask 255.0.0.0 ==
>> 10.0.0.0/8 or 10.169.0.0 mask 255.255.0.0 == 10.169.0.0/16
> 
> Your expectations are not mine.  Got a citation that says your
> examples are not only correct, but to be insisted on?

Well, the number after the slash is the prefix length (contigous bits), 
so you've either overspecified the network part or the mask doesn't 
cover enough of the prefix.

https://tools.ietf.org/html/rfc4632

>> Should that generate an error message?
> 
> Why?  ntpd never complained about the mask before.  I've never seen
> any program complain about such usage.  It is very convenient as
> the user can simply cut/paste rfom his 'ifconfig' or 'ip addr' output.

So what did it do in this case?  It would either ignore some part of the 
IP address being specified (which could then be any number, including 
the canonical "0") or not apply the given mask correctly.


-- 
Achim.

(on the road :-)