Fix some portability bugs I'd introduced into inet/cidr code ---

shifting by the word width is not defined by ANSI C...

diff --git a/src/backend/utils/adt/network.c b/src/backend/utils/adt/network.c
index 52f4e8ecd2fdc9ec7bf401261b9f155692feb8d6..75527fda026a8681293c447d9776fcbc9128de81 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.
  *
- *     $Header: /cvsroot/pgsql/src/backend/utils/adt/network.c,v 1.26 2000/11/10 20:13:25 tgl Exp $
+ *     $Header: /cvsroot/pgsql/src/backend/utils/adt/network.c,v 1.27 2000/11/25 21:30:54 tgl Exp $
  *
  *     Jon Postel RIP 16 Oct 1998
  */
@@ -418,7 +418,13 @@ network_broadcast(PG_FUNCTION_ARGS)
                /* It's an IP V4 address: */
                unsigned long mask = 0xffffffff;
 
-               mask >>= ip_bits(ip);
+               /* Shifting by 32 or more bits does not yield portable results,
+                * so don't try it.
+                */
+               if (ip_bits(ip) < 32)
+                       mask >>= ip_bits(ip);
+               else
+                       mask = 0;
 
                ip_v4addr(dst) = htonl(ntohl(ip_v4addr(ip)) | mask);
        }
@@ -451,7 +457,13 @@ network_network(PG_FUNCTION_ARGS)
                /* It's an IP V4 address: */
                unsigned long mask = 0xffffffff;
 
-               mask <<= (32 - ip_bits(ip));
+               /* Shifting by 32 or more bits does not yield portable results,
+                * so don't try it.
+                */
+               if (ip_bits(ip) > 0)
+                       mask <<= (32 - ip_bits(ip));
+               else
+                       mask = 0;
 
                ip_v4addr(dst) = htonl(ntohl(ip_v4addr(ip)) & mask);
        }
@@ -484,7 +496,13 @@ network_netmask(PG_FUNCTION_ARGS)
                /* It's an IP V4 address: */
                unsigned long mask = 0xffffffff;
 
-               mask <<= (32 - ip_bits(ip));
+               /* Shifting by 32 or more bits does not yield portable results,
+                * so don't try it.
+                */
+               if (ip_bits(ip) > 0)
+                       mask <<= (32 - ip_bits(ip));
+               else
+                       mask = 0;
 
                ip_v4addr(dst) = htonl(mask);
 
@@ -512,7 +530,13 @@ v4bitncmp(unsigned long a1, unsigned long a2, int bits)
 {
        unsigned long mask;
 
-       mask = (0xFFFFFFFFL << (32 - bits)) & 0xFFFFFFFFL;
+       /* Shifting by 32 or more bits does not yield portable results,
+        * so don't try it.
+        */
+       if (bits > 0)
+               mask = (0xFFFFFFFFL << (32 - bits)) & 0xFFFFFFFFL;
+       else
+               mask = 0;
        a1 = ntohl(a1);
        a2 = ntohl(a2);
        if ((a1 & mask) < (a2 & mask))
@@ -530,7 +554,13 @@ v4addressOK(unsigned long a1, int bits)
 {
        unsigned long mask;
 
-       mask = (0xFFFFFFFFL << (32 - bits)) & 0xFFFFFFFFL;
+       /* Shifting by 32 or more bits does not yield portable results,
+        * so don't try it.
+        */
+       if (bits > 0)
+               mask = (0xFFFFFFFFL << (32 - bits)) & 0xFFFFFFFFL;
+       else
+               mask = 0;
        a1 = ntohl(a1);
        if ((a1 & mask) == a1)
                return true;