Re: [BUGS] Bug in create operator and/or initdb

when my cidr datatype was integrated into pgsql, the decision was made to
incorporate a copy of bind's inet_net_pton.c rather than add a link-time
dependence to libbind.a (libbind.so).  thus, when this bug was fixed in
2003:

----------------------------
revision 1.14
date: 2003/08/20 02:21:08;  author: marka;  state: Exp;  lines: +10 -4
1580.   [bug]           inet_net_pton() didn't fully handle implicit                       multicast IPv4 network
addresses.

the pgsql "fork" of this code did not benefit from the fix.  the patch was:

Index: inet_net_pton.c
===================================================================
RCS file: /proj/cvs/prod/bind8/src/lib/inet/inet_net_pton.c,v
retrieving revision 1.13
retrieving revision 1.14
diff -u -r1.13 -r1.14
--- inet_net_pton.c     27 Sep 2001 15:08:38 -0000      1.13
+++ inet_net_pton.c     20 Aug 2003 02:21:08 -0000      1.14
@@ -16,7 +16,7 @@ */#if defined(LIBC_SCCS) && !defined(lint)
-static const char rcsid[] = "$Id: inet_net_pton.c,v 1.13 2001/09/27 15:08:38 marka Exp $";
+static const char rcsid[] = "$Id: inet_net_pton.c,v 1.14 2003/08/20 02:21:08 marka Exp $";#endif#include
"port_before.h"
@@ -59,7 +59,7 @@ *     Paul Vixie (ISC), June 1996 */static int
-inet_net_pton_ipv4( const char *src, u_char *dst, size_t size) {
+inet_net_pton_ipv4(const char *src, u_char *dst, size_t size) {       static const char xdigits[] =
"0123456789abcdef";      static const char digits[] = "0123456789";       int n, ch, tmp = 0, dirty, bits;
 
@@ -152,7 +152,7 @@               if (*odst >= 240)       /* Class E */                       bits = 32;
elseif (*odst >= 224)  /* Class D */
 
-                       bits = 4;
+                       bits = 8;               else if (*odst >= 192)  /* Class C */                       bits = 24;
            else if (*odst >= 128)  /* Class B */
 
@@ -160,8 +160,14 @@               else                    /* Class A */                       bits = 8;
/*If imputed mask is narrower than specified octets, widen. */
 
-               if (bits >= 8 && bits < ((dst - odst) * 8))
+               if (bits < ((dst - odst) * 8))                       bits = (dst - odst) * 8;
+               /*
+                * If there are no additional bits specified for a class D
+                * address adjust bits to 4.
+                */
+               if (bits == 8 && *odst == 224)
+                       bits = 4;       }       /* Extend network to cover the actual mask. */       while (bits >
((dst- odst) * 8)) {
 

re:

> To: Steve Atkins <steve@blighty.com>
> Cc: pgsql-hackers <pgsql-hackers@postgresql.org>, paul@vix.com
> Subject: Re: [HACKERS] [BUGS] Bug in create operator and/or initdb 
> Comments: In-reply-to Steve Atkins <steve@blighty.com>
>     message dated "Mon, 31 Jan 2005 07:23:05 -0800"
> Date: Mon, 31 Jan 2005 12:16:26 -0500
> From: Tom Lane <tgl@sss.pgh.pa.us>
> 
> Steve Atkins <steve@blighty.com> writes:
> > The cidr type, including it's external interface, is simply broken.
> 
> That is a large claim that I don't think you have demonstrated.
> The only one of your examples that seems to me to contradict the
> documentation is this one:
> 
>  steve=# select '224.0.0.0'::cidr;
>       cidr     
>   -------------
>    224.0.0.0/4
> 
> which should be /32 according to what the docs say:
> 
> : If y is omitted, it is calculated using assumptions from the older
> : classful network numbering system, except that it will be at least large
> : enough to include all of the octets written in the input.
> 
> The bogus netmask is in turn responsible for this case:
> 
>   steve=# select '224.10.0.0'::cidr;
>   ERROR:  invalid cidr value: "224.10.0.0"
>   DETAIL:  Value has bits set to right of mask.
> 
> 
> Looking at the source code, there seems to be a special case for "class D"
> network numbers that causes the code not to extend y to cover the
> supplied inputs:
> 
>     /* If no CIDR spec was given, infer width from net class. */
>     if (bits == -1)
>     {
>         if (*odst >= 240)        /* Class E */
>             bits = 32;
>         else if (*odst >= 224)    /* Class D */
>             bits = 4;
>         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 >= 8 && bits < ((dst - odst) * 8))
>             ^^^^^^^^^
>             bits = (dst - odst) * 8;
>     }
> 
> I think the test for "bits >= 8" should be removed.  Does anyone know
> why it's there?
> 
>             regards, tom lane