This patch change djbdns's dnscache program so that it will ignore the
IP address given in the ignoreip file.  I wrote this patch because of
Verisign's oh-so helpful wildcard A record for *.COM and *.NET.

If you have djbdns-1.05-ignoreip.patch installed, back it out like this:
    cd /usr/local/src/djbdns-1.05
    patch -R <djbdns-1.05-ignoreip.patch

Install the patch like this:
    cd /usr/local/src/djbdns-1.05
    patch <djbdns-1.05-ignoreip2.patch
    svc -d /service/dnscache
    make setup check
    svc -u /service/dnscache

Configure it to ignore Verisign's wildcard record like this:
    echo 64.94.110.11 >/service/dnscache/root/ignoreip
    svc -t /service/dnscache

Configure it to ignore all the cretins like this:
awk '{print $2}' <<EOF >/service/dnscache/root/ignoreip
         *.ac            194.205.62.122
         *.cc            206.253.214.102
         *.com           64.94.110.11
         *.cx            219.88.106.80
         *.museum        195.7.77.20
         *.net           64.94.110.11
         *.nu            64.55.105.9
                   and   212.181.91.6
         *.ph            203.119.4.6
         *.sh            194.205.62.62
         *.tm            194.205.62.62
         *.ws            216.35.187.246
EOF
    svc -t /service/dnscache

J.P. Larocque contributes a script which updates root/ignoreip:
    http://ely.ath.cx/~piranha/software/ignoreip-update/ignoreip-update-0.1

If root/ignoreip is not present, no addresses will be ignored.

--
--My blog is at angry-economist.russnelson.com  | Free markets express in the
Crynwr sells support for free software  | PGPok | practical world our belief
521 Pleasant Valley Rd. | +1 315 268 1925 voice | that there is that of God
Potsdam, NY 13676-3213  | +1 315 268 9201 FAX   | in all people. -Chris V.


diff -u orig/dnscache.c ./dnscache.c
--- orig/dnscache.c	2001-02-11 16:11:45.000000000 -0500
+++ ./dnscache.c	2003-09-16 23:23:36.000000000 -0400
@@ -23,6 +23,8 @@
 #include "okclient.h"
 #include "droproot.h"
 
+stralloc ignoreip = {0};
+
 static int packetquery(char *buf,unsigned int len,char **q,char qtype[2],char qclass[2],char id[2])
 {
   unsigned int pos;
@@ -389,6 +391,7 @@
 int main()
 {
   char *x;
+  unsigned int i, j, k;
   unsigned long cachesize;
 
   x = env_get("IP");
@@ -431,6 +434,20 @@
   if (!cache_init(cachesize))
     strerr_die3x(111,FATAL,"not enough memory for cache of size ",x);
 
+  if (openreadclose("ignoreip",&ignoreip,64) < 0) 
+    strerr_die2x(111,FATAL,"trouble reading ignoreip");
+  for(j = k = i = 0; i < ignoreip.len; i++)
+    if (ignoreip.s[i] == '\n')  {
+      ignoreip.s[i] = '\0';
+      if (j + 4 > i)
+        strerr_die3x(111,FATAL,"badly malformed ip4 address ",ignoreip.s+k);
+      if (!ip4_scan(ignoreip.s+k,ignoreip.s+j))
+        strerr_die3x(111,FATAL,"unable to parse address in ignoreip ",ignoreip.s+k);
+      j += 4;
+      k = i + 1;
+    }
+  ignoreip.len = j;
+
   if (env_get("HIDETTL"))
     response_hidettl();
   if (env_get("FORWARDONLY"))
diff -u orig/query.c ./query.c
--- orig/query.c	2001-02-11 16:11:45.000000000 -0500
+++ ./query.c	2003-09-16 23:31:41.000000000 -0400
@@ -13,6 +13,8 @@
 #include "response.h"
 #include "query.h"
 
+extern stralloc ignoreip;
+
 static int flagforwardonly = 0;
 
 void query_forwardonly(void)
@@ -193,6 +195,7 @@
   int k;
   int p;
   int q;
+  unsigned int ii;
 
   errno = error_io;
   if (state == 1) goto HAVEPACKET;
@@ -643,6 +646,9 @@
         pos = dns_packet_copy(buf,len,pos,header,10); if (!pos) goto DIE;
         if (byte_equal(header + 8,2,"\0\4")) {
           pos = dns_packet_copy(buf,len,pos,header,4); if (!pos) goto DIE;
+          if (ignoreip.len)
+	    for(ii = 0; ii < ignoreip.len; ii+= 4)
+	      if (byte_equal(header,4,ignoreip.s+ii)) goto NXDOMAIN;
           save_data(header,4);
           log_rr(whichserver,t1,DNS_T_A,header,4,ttl);
         }