dnswall does not filter 192.0.2.0/24 as defined in RFC 3330

[GoogleCodeExporter]

RFC 3330 defines some ranges which can not be found on the internet. for 
example 192.0.2.0/24. As a result those ranges can be used behind NAT 
like usual RFC 1918 IPs.

dnswall should make sure those ranges are not returned neither.

The trivial patch provided below add filtering for :

   192.0.2.0/24 - This block is assigned as "TEST-NET" for use in
   documentation and example code.  It is often used in conjunction with
   domain names example.com or example.net in vendor and protocol
   documentation.  Addresses within this block should not appear on the
   public Internet.

You may consider filtering for this range as well :

   198.18.0.0/15 - This block has been allocated for use in benchmark
   tests of network interconnect devices.  Its use is documented in
   [RFC2544].

diff -ur dnswall.org/src/dnswall.c dnswall.documentation/src/dnswall.c
--- dnswall.org/src/dnswall.c   2007-11-14 19:59:52.000000000 +0000
+++ dnswall.documentation/src/dnswall.c 2010-01-01 
15:25:31.000000000 +0000
@@ -94,6 +94,10 @@
      (ptr[0] == 192 && ptr[1] == 168))
     return 0;

+  // Documentation
+  if (ptr[0] == 192 && ptr[1] == 0 && ptr[2] == 2)
+    return 0;
+
   // Multicast
   // (we are unable to determine the groups internal machines
   // belong to, so we have to block everything)

Original issue reported on code.google.com by thomas.mangin on 1 Jan 2010 at 3:40