[pkg-netfilter-team] Bug#886321: (no subject)

[Martin Großhauser]

> Package: ipset
> Version: 6.30-2
> Severity: normal
> 
> Dear Maintainer,
> 
> When adding an entry to an ipset, if you do not specify a full dotted quad,
> what gets added is not what you might reasonably expect
> 
> For example, if you were to type:
> 
> ipset add FOO 192.168/16
> 
> where FOO is the name of an existing inet family hash:ip set what it adds
> is 192.0.0.0/16 - as though treating the 168 as 0.0.168, perhaps.

192.168/16 is indeed interpreted as 192.0.0.168/16. This is done
intentionally by inet_aton(), which allows IP addresses in the formats
'a.b.c.', 'a.b.c', 'a.b' and 'a' [1].

An *expired* IETF draft [2] mentions that behaviour as "non-standard"
but "very popular" and "a de facto standard for the textual
representation of IPv4 addresses". [2]

According to Wikipedia "No formal specification of this textual IP
address representation exists." [3]

So I would say it's a feature, not a bug, and there's nothing wrong here.

[1] https://linux.die.net/man/3/inet_aton
[2] https://tools.ietf.org/html/draft-main-ipaddr-text-rep-02
[3] https://en.wikipedia.org/wiki/Dot-decimal_notation