Add DNS entries to the hosts "ctrladdr" knows about.

(By fetching a zone transfer for $OURDOMAIN, and hunting through it
for addresses on the control network.)

configure

@@ -698,6 +698,7 @@ CXX
 AR
 RANLIB
 STRIP
+DIG
 ELVIN_CONFIG
 JAVAC
 JAR
@@ -4442,6 +4443,46 @@ fi
 
 
 
+# Extract the first word of "dig", so it can be a program name with args.
+set dummy dig; ac_word=$2
+{ $as_echo "$as_me:$LINENO: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if test "${ac_cv_path_DIG+set}" = set; then
+  $as_echo_n "(cached) " >&6
+else
+  case $DIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_DIG="$DIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_path_DIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+DIG=$ac_cv_path_DIG
+if test -n "$DIG"; then
+  { $as_echo "$as_me:$LINENO: result: $DIG" >&5
+$as_echo "$DIG" >&6; }
+else
+  { $as_echo "$as_me:$LINENO: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
 # Extract the first word of "elvin-config", so it can be a program name with args.
 set dummy elvin-config; ac_word=$2
 { $as_echo "$as_me:$LINENO: checking for $ac_word" >&5
@@ -7429,7 +7470,7 @@ outfiles="$outfiles Makeconf GNUmakefile \
 	utils/spewconlog utils/xlogin \
 	utils/opsdb_control utils/opsdb_control.proxy \
 	utils/remove_old_www utils/epmodeset \
-	utils/mkblob utils/rmblob \
+	utils/mkblob utils/rmblob utils/ctrladdr \
 	www/GNUmakefile www/defs.php3 www/dbdefs.php3 www/xmlrpc.php3 \
 	www/xmlrpcpipe.php3 \
 	www/swish.conf www/websearch \
@@ -7568,7 +7609,7 @@ outfiles="$outfiles clientside/GNUmakefile \
  clientside/tmcc/freebsd10/GNUmakefile clientside/tmcc/freebsd10/netif-emulab \
  clientside/tmcc/cygwinxp/GNUmakefile clientside/tmcc/dp/GNUmakefile \
  clientside/tmcc/openbsd/GNUmakefile clientside/tmcc/ron/GNUmakefile \
- clientside/tmcc/plab/GNUmakefile \
+ clientside/tmcc/plab/GNUmakefile clientside/tmcc/cygwinseven/GNUmakefile \
  clientside/os/dijkstra/GNUmakefile clientside/os/genhostsfile/GNUmakefile \
  clientside/os/growdisk/GNUmakefile \
  clientside/os/zapdisk/GNUmakefile \

configure.in

@@ -86,6 +86,7 @@ AC_CHECK_TOOL(STRIP,strip)
 
 AC_EXEEXT
 
+AC_PATH_PROG(DIG,dig)
 AC_PATH_PROG(ELVIN_CONFIG,elvin-config)
 AC_PATH_PROG(JAVAC,javac)
 AC_PATH_PROG(JAR,jar)

utils/ctrladdr.in

@@ -6,6 +6,26 @@
 # All rights reserved.
 #
 
+#
+# Show (un)allocated addresses on the control net.
+#
+# By default, the output is supposed to be easy to parse and simply
+# displays the first available address.  More than one available address
+# can be requested with the "-n" option (e.g. "-n 10" will show the
+# first ten unallocated addresses).  "-n 0" will show every free
+# address on the subnet.
+# 
+# The "-a" option (meant more for human consumption) also describes
+# allocated addresses.  For instance, "ctrladdr -a -n 0" will show
+# every address on the control net, and what it's used for (if
+# anything).  "-r" will compress ranges of consecutive free addresses
+# onto a single line.
+# 
+# To test whether a particular address is in use, invoke it as (e.g.)
+# "ctrladdr -t 155.98.36.1".  This will give an exit code of 0 if the
+# address is available, and 1 if used.  Any other options are ignored
+# if "-t" is specified.
+
 use English;
 use Getopt::Std;
 use strict;
@@ -17,6 +37,8 @@ use Socket;
 my $TB			= "@prefix@";
 my $control_network     = "@CONTROL_NETWORK@";
 my $control_netmask     = "@CONTROL_NETMASK@";
+my $DIG                 = "@DIG@";
+my $ourdomain           = "@OURDOMAIN@";
 
 #
 # Turn off line buffering on output
@@ -72,6 +94,10 @@ if( $options{ 'r' } ) {
 
 usage() unless @ARGV == 0;
 
+
+my $net = unpack( "N", inet_aton( $control_network ) );
+my $mask = unpack( "N", inet_aton( $control_netmask ) );
+
 my %used = ();
 
 sub show($) {
@@ -97,13 +123,34 @@ sub range_done($) {
 	} else {
 	    print inet_ntoa( pack( "N", $range_start ) ) . "-" .
 		inet_ntoa( pack( "N", $i - 1 ) ) . " (" . 
-		( $i - 1 - $range_start ) . " addresses)\n";
+		( $i - $range_start ) . " addresses)\n";
 	}
 
 	$range_start = undef;
     }
 }
 
+#
+# Populate the set of known addresses.
+#
+if( open( DNS, "$DIG -t axfr $ourdomain |" ) ) {
+    while( <DNS> ) {
+	if( /^([-a-zA-Z0-9.]+)\.\s+[0-9]+\s+IN\s+A\s+([0-9.]+)/ ) {
+	    my $dns_name = $1;
+	    my $dns_addr = $2;
+	    my $dns_addr_num = unpack( "N", inet_aton( $2 ) );
+
+	    if( ( $dns_addr_num & $mask ) == $net ) {
+		$used{ $dns_addr } = $dns_name;
+	    }
+	}
+    }
+    close( DNS );
+} else {
+    print STDERR "Could not read zone transfer\n";
+    exit( 1 );
+}
+
 my $result = DBQueryWarn( "SELECT IP, node_id FROM interfaces WHERE " .
 			  "role='ctrl';" );
 if( !$result ) {
@@ -129,12 +176,12 @@ while( my( $IP ) = $result->fetchrow_array() ) {
 
 # XXX Find any other addresses which are allocated, and add them to %used
 
-my $net = unpack( "N", inet_aton( $control_network ) );
-my $mask = unpack( "N", inet_aton( $control_netmask ) );
-
 $used{ inet_ntoa( pack( "N", $net ) ) } = "the network";
 $used{ inet_ntoa( pack( "N", $net | ~$mask ) ) } = "broadcast";
 
+#
+# The list is complete... ready to compute the output.
+#
 if( $test ) {
     my $t = unpack( "N", inet_aton( $test ) );