Sorting for the inet data type randomly returns the wrong result

when you have networks with the same prefix, but different netmasks.

This is due to the fact that occassionally there is random
(uninitialized?)
data in the extra bits past the point where the netmask cares about
them.

ie (real data from a real live database):

  10.0/10 == 00001010.00100000.00100000.00011000
  10.0/11 == 00001010.00000000.00000000.00000000
                        ^ Bad data, normally never seen

The v4bitncmp() function was only taking one bit length argument so
it would determine that the networks were different, even though
they really aren't (and the netmask test wouldn't be used).  This
ONLY happens if the tuple with the longer bit length is used as the
ip_bits() for the v4bitncmp call AND there happens to be junk data
in place in the shorter tuple.  Odd and random, but I saw it happen
a couple times so...

Ryan Mooney

diff --git a/src/backend/utils/adt/network.c b/src/backend/utils/adt/network.c
index d1173aeccf7ef68b01c8e414382ec43d5318abdd..72607f7f3d9fff2e6c90723451b4037421e4316b 100644 (file)
--- a/src/backend/utils/adt/network.c
+++ b/src/backend/utils/adt/network.c
@@ -3,7 +3,7 @@
  *     is for IP V4 CIDR notation, but prepared for V6: just
  *     add the necessary bits where the comments indicate.
  *
- *     $Id: network.c,v 1.18 2000/02/21 18:49:54 tgl Exp $
+ *     $Id: network.c,v 1.19 2000/03/07 23:01:43 momjian Exp $
  *     Jon Postel RIP 16 Oct 1998
  */
 
@@ -18,7 +18,7 @@
 #include "postgres.h"
 #include "utils/builtins.h"
 
-static int     v4bitncmp(unsigned int a1, unsigned int a2, int bits);
+static int     v4bitncmp(unsigned int a1, unsigned int a2, int bits1, int bits2);
 
 /*
  *     Access macros.  Add IPV6 support.
@@ -137,7 +137,7 @@ network_lt(inet *a1, inet *a2)
                return FALSE;
        if ((ip_family(a1) == AF_INET) && (ip_family(a2) == AF_INET))
        {
-               int                     order = v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a2));
+               int                     order = v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1), ip_bits(a2));
 
                return ((order < 0) || ((order == 0) && (ip_bits(a1) < ip_bits(a2))));
        }
@@ -166,7 +166,7 @@ network_eq(inet *a1, inet *a2)
        if ((ip_family(a1) == AF_INET) && (ip_family(a2) == AF_INET))
        {
                return ((ip_bits(a1) == ip_bits(a2))
-                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1)) == 0));
+                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1), ip_bits(a2)) == 0));
        }
        else
        {
@@ -192,7 +192,7 @@ network_gt(inet *a1, inet *a2)
                return FALSE;
        if ((ip_family(a1) == AF_INET) && (ip_family(a2) == AF_INET))
        {
-               int                     order = v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a2));
+               int                     order = v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1), ip_bits(a2));
 
                return ((order > 0) || ((order == 0) && (ip_bits(a1) > ip_bits(a2))));
        }
@@ -222,7 +222,7 @@ network_sub(inet *a1, inet *a2)
        if ((ip_family(a1) == AF_INET) && (ip_family(a2) == AF_INET))
        {
                return ((ip_bits(a1) > ip_bits(a2))
-                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a2)) == 0));
+                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1), ip_bits(a2)) == 0));
        }
        else
        {
@@ -242,7 +242,7 @@ network_subeq(inet *a1, inet *a2)
        if ((ip_family(a1) == AF_INET) && (ip_family(a2) == AF_INET))
        {
                return ((ip_bits(a1) >= ip_bits(a2))
-                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a2)) == 0));
+                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1), ip_bits(a2)) == 0));
        }
        else
        {
@@ -262,7 +262,7 @@ network_sup(inet *a1, inet *a2)
        if ((ip_family(a1) == AF_INET) && (ip_family(a2) == AF_INET))
        {
                return ((ip_bits(a1) < ip_bits(a2))
-                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1)) == 0));
+                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1), ip_bits(a2)) == 0));
        }
        else
        {
@@ -282,7 +282,7 @@ network_supeq(inet *a1, inet *a2)
        if ((ip_family(a1) == AF_INET) && (ip_family(a2) == AF_INET))
        {
                return ((ip_bits(a1) <= ip_bits(a2))
-                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1)) == 0));
+                && (v4bitncmp(ip_v4addr(a1), ip_v4addr(a2), ip_bits(a1), ip_bits(a2)) == 0));
        }
        else
        {
@@ -476,13 +476,16 @@ network_netmask(inet *ip)
  */
 
 static int
-v4bitncmp(unsigned int a1, unsigned int a2, int bits)
+v4bitncmp(unsigned int a1, unsigned int a2, int bits1, int bits2)
 {
        unsigned long mask = 0;
-       int                     i;
+       int                     i, bits;
+
+       bits=(bits1 < bits2) ? bits1 : bits2;
 
        for (i = 0; i < bits; i++)
                mask = (mask >> 1) | 0x80000000;
+
        a1 = ntohl(a1);
        a2 = ntohl(a2);
        if ((a1 & mask) < (a2 & mask))