Re: Cleaning up the INET/CIDR mess

Andrew - Supernews wrote:
> On 2006-01-25, Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> wrote:
> > Agreed. 10.1 as 10.0.0.1 is an old behavior which has been removed from
> > most modern versions of networking tools.
>
> Indeed so. However the current behaviour has neither the merit of being
> traditional nor the merit of being logical:
>
> => select '10.1'::cidr;
> cidr
> -------------
> 10.1.0.0/16
> (1 row)
>
> => select '128.1'::cidr;
> cidr
> --------------
> 128.1.0.0/16
> (1 row)
>
> => select '192.1'::cidr;
> cidr
> --------------
> 192.1.0.0/24
> (1 row)
>
> Having the behaviour be dependent on which part of the IP space is used
> is a total nonsense on the modern, CIDR, internet! The C in CIDR even
> stands for "Classless", so how can you ever justify introducing _new_,
> non-traditional, dependencies on the traditional classes?

This is coming from inet_net_pton.c, which we got from:

* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1996,1999 by Internet Software Consortium.

...

if (bits == -1)
{
if (*odst >= 240) /* Class E */
bits = 32;
else if (*odst >= 224) /* Class D */
bits = 8;
else if (*odst >= 192) /* Class C */
bits = 24;
else if (*odst >= 128) /* Class B */
bits = 16;
else
/* Class A */
bits = 8;
/* If imputed mask is narrower than specified octets, widen. */
if (bits < ((dst - odst) * 8))
bits = (dst - odst) * 8;

...

test=> select '11'::cidr;
cidr
------------
11.0.0.0/8
(1 row)

We are doing our best here to follow industry standards on how things
should behave.

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
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