contrib/make-ssh-known-hosts.pl - platform/external/openssh - Gitiles

 #!/usr/bin/perl -w
 # -*- perl -*-
 ######################################################################
 # make-ssh-known-hosts.pl -- Make ssh-known-hosts file
 # Copyright (c) 1995 Tero Kivinen
 # All Rights Reserved.
 #
 # Make-ssh-known-hosts is distributed in the hope that it will be
 # useful, but WITHOUT ANY WARRANTY.  No author or distributor accepts
 # responsibility to anyone for the consequences of using it or for
 # whether it serves any particular purpose or works at all, unless he
 # says so in writing.  Refer to the GNU General Public License for full
 # details.
 #
 # Everyone is granted permission to copy, modify and redistribute
 # make-ssh-known-hosts, but only under the conditions described in
 # the GNU General Public License.  A copy of this license is supposed to
 # have been given to you along with make-ssh-known-hosts so you can
 # know your rights and responsibilities.  It should be in a file named
 # gnu-COPYING-GPL.  Among other things, the copyright notice and this notice
 # must be preserved on all copies.
 ######################################################################
 #         Program: make-ssh-known-hosts.pl
 #	  $Source: /var/cvs/openssh/contrib/Attic/make-ssh-known-hosts.pl,v $
 #	  Author : $Author: damien $
 #
 #	  (C) Tero Kivinen 1995 <Tero.Kivinen@hut.fi>
 #
 #	  Creation          : 19:52 Jun 27 1995 kivinen
 #	  Last Modification : 00:07 Jul  8 1998 kivinen
 #	  Last check in     : $Date: 2000/03/15 01:13:03 $
 #	  Revision number   : $Revision: 1.1 $
 #	  State             : $State: Exp $
 #	  Version	    : 1.343
 #	  Edit time	    : 242 min
 #
 #	  Description       : Make ssh-known-host file from dns data.
 #
 #	  $Log: make-ssh-known-hosts.pl,v $
 #	  Revision 1.1  2000/03/15 01:13:03  damien
 #	   - Created contrib/ subdirectory. Included helpers from Phil Hands'
 #	     Debian package, README file and chroot patch from Ricardo Cerqueira
 #	     <rmcc@clix.pt>
 #	   - Moved gnome-ssh-askpass.c to contrib directory and reomved config
 #	     option.
 #	   - Slight cleanup to doc files
 #
 #	  Revision 1.6  1998/07/08 00:44:23  kivinen
 #	  	Fixed to understand bind 8 nslookup output.
 #
 # Revision 1.5  1998/04/30  01:53:33  kivinen
 # 	Moved kill before close and added sending SIGINT first and
 # 	then 1 second sleep before sending SIGKILL.
 #
 #	  Revision 1.4  1998/04/17 00:39:19  kivinen
 #	  	Changed to close ssh program filedescriptor before killing it.
 #	  	Removed ^ from the password matching prompt.
 #
 #	  Revision 1.3  1997/04/17 04:21:27  kivinen
 #	  	Changed to use 3des by default.
 #
 #	  Revision 1.2  1997/03/26 07:14:01  kivinen
 #	  	Added EWOULDBLOCK.
 #
 #	  Revision 1.1.1.1  1996/02/18 21:38:10  ylo
 #	  	Imported ssh-1.2.13.
 #
 # Revision 1.4  1995/10/02  01:23:45  ylo
 # 	Ping packet size fixes from Kivinen.
 #
 # Revision 1.3  1995/08/29  22:37:39  ylo
 # 	Now uses GlobalKnownHostsFile and UserKnownHostsFile.
 #
 # Revision 1.2  1995/07/15  13:26:37  ylo
 # 	Changes from kivinen.
 #
 # Revision 1.1.1.1  1995/07/12  22:41:05  ylo
 # Imported ssh-1.0.0.
 #
 #
 #
 # If you have any useful modifications or extensions please send them to
 # Tero.Kivinen@hut.fi
 #
 ######################################################################
 # initialization

 require 5.000;
 use Getopt::Long;
 use FileHandle;
 use POSIX;
 use Socket;
 use Fcntl;

 $version = ' $Id: make-ssh-known-hosts.pl,v 1.1 2000/03/15 01:13:03 damien Exp $ ';

 $command_line = "$0 ";
 foreach $a (@ARGV) {
     $command_line .= $a . " ";
 }
 STDERR->autoflush(1);

 ######################################################################
 # default values for options

 $debug = 5;
 $defserver = '';
 $bell='\a';
 $public_key = '/etc/ssh_host_key.pub';
 $private_ssh_known_hosts = "/tmp/ssh_known_hosts$$";
 $timeout = 60;
 $ping_timeout = 3;
 $passwordtimeout = undef;
 $trustdaemon = 1;
 $domainnamesplit = 0;
 $recursive = 1;

 ######################################################################
 # Programs and their options

 $nslookup = "nslookup";

 $ssh="ssh -a -c 3des -x -o 'ConnectionAttempts 1' -o 'FallBackToRsh no' -o 'GlobalKnownHostsFile /dev/null' -o 'KeepAlive yes' -o 'StrictHostKeyChecking no' -o 'UserKnownHostsFile $private_ssh_known_hosts'";
 $sshdisablepasswordoption="-o 'BatchMode yes' -o 'PasswordAuthentication no'";

 ######################################################################
 # Cleanup and initialization

 unlink($private_ssh_known_hosts);
 $sockaddr = 'S n a4 x8';
 ($junk, $junk, $sshport) = getservbyname("ssh", "tcp");
 if (!defined($sshport)) {
     $sshport = 22;
 }
 ($tcpprotoname, $junk, $tcpproto) = getprotobyname('tcp');
 defined($tcpprotoname) || die "getprotobyname : $!";

 ######################################################################
 # Parse options

 GetOptions("initialdns=s", "server=s", "subdomains=s",
 	   "debug=i", "timeout=i", "passwordtimeout=i",
 	   "trustdaemon!", "domainnamesplit", "silent",
 	   "nslookup=s", "pingtimeout=i", "recursive!",
 	   "keyscan",
 	   "ssh=s")
     || die "Getopt : $!";

 if (defined($opt_initialdns)) { $defserver = $opt_initialdns; }

 if (defined($opt_server)) { $server = $opt_server; }

 if (defined($opt_subdomains)) { @subdomains = split(/,/, $opt_subdomains); }

 if (defined($opt_debug)) { $debug = $opt_debug; }

 if (defined($opt_timeout)) { $timeout = $opt_timeout; }

 if (defined($opt_pingtimeout)) { $ping_timeout = $opt_pingtimeout; }

 if (defined($opt_passwordtimeout)) {
     $passwordtimeout = $opt_passwordtimeout;
     $sshdisablepasswordoption = '';
 }

 if (defined($opt_trustdaemon)) { $trustdaemon = $opt_trustdaemon; }

 if (defined($opt_recursive)) { $recursive = $opt_recursive; }

 if (defined($opt_domainnamesplit)) { $domainnamesplit = $opt_domainnamesplit; }

 if (defined($opt_silent)) { $bell = ''; }

 if (defined($opt_nslookup)) { $nslookup = $opt_nslookup; }

 if (defined($opt_ssh)) { $ssh = $opt_ssh; } else {
     $ssh = "$ssh $sshdisablepasswordoption";
 }

 if ($#ARGV == 0) {
     $domain = "\L$ARGV[0]\E";
     $grep_yes = '.*';
     $grep_no = '^$';
 } elsif ($#ARGV == 1) {
     $domain = "\L$ARGV[0]\E";
     $grep_yes = $ARGV[1];
     $grep_no = '^$';
 } elsif ($#ARGV == 2) {
     $domain = "\L$ARGV[0]\E";
     $grep_yes = $ARGV[1];
     $grep_no = $ARGV[2];
 } else {
     print(STDERR "$0 [--initialdns initial_dns_server] [--server dns_server] [--subdomains sub.sub.domain,sub.sub,sub,] [--debug debug_level] [--timeout ssh_exec_timeout_in_secs] [--pingtimeout ping_timeout_in_secs] [--passwordtimeout timeout_for_password_in_secs] [--notrustdaemon] [--norecursive] [--domainnamesplit] [--silent] [--keyscan] [--nslookup path_to_nslookup] [--ssh path_to_ssh] full.domain [ host_info_take_regexp [ host_info_remove_regex ]]\n");
     exit(1);
 }

 ######################################################################
 # Check that ssh program exists

 if (system("$ssh > /dev/null 2>&1 ") != 256) {
     print(STDERR "Error: Could not run ssh program ($ssh): $!\nError: Try giving the path to it with --ssh option\n");
     exit(1);
 }

 ######################################################################
 # Generate subdomains list

 if (!$domainnamesplit) {
     debug(6, "Auto splitting host entries");
 } elsif (!defined(@subdomains)) {
     debug(6, "Generating subdomain list");

     # split domain to pieces
     @domain_pieces = split(/\./, $domain);

     # add empty domain part
     push(@subdomains, '');

     # add rest parts, except the one before full domain name
     $entry='';
     for(; $#domain_pieces > 1; ) {
 	$entry .= "." . shift(@domain_pieces);
 	push(@subdomains, $entry);
     }

     # add full domain name
     push(@subdomains, ".$domain");
     debug(5, "Subdomain list: " . join(',', @subdomains));
 } else {
     debug(5, "Using given subdomain list:" . join(',', @subdomains));
 }

 ######################################################################
 # finding SOA entry for domain

 @other_servers = ();
 if (!defined($server)) {
     debug(6, "Finding DNS database SOA entry");

     ($server, @other_servers) = find_soa($domain, $defserver);

     if (!defined($server)) {
 	print(STDERR "Error: Could not find DNS SOA entry from default dns server\nError: Try giving the initial nameserver with --initialdns option\n");
 	exit(1);
     } else {
 	debug(5, "DNS server found : $server");
     }
 } else {
     debug(5, "Using given DNS server : $server");
 }

 ######################################################################
 # Print header

 ($name, $junk, $junk, $junk, $junk, $junk, $gecos) = getpwuid($<);
 $gecos =~ s/,.*$//g;

 if (!defined($opt_keyscan)) {
     print(STDOUT "# This file is generated with make-ssh-known-hosts.pl\n");
     print(STDOUT "#$version\n");
     print(STDOUT "# with command line :\n");
     print(STDOUT "# $command_line\n");
     print(STDOUT "#\n");
     print(STDOUT "# The script was run by $gecos ($name) at " . localtime() . "\n");
     print(STDOUT "# using perl ($^X) version $].\n");
 }

 ######################################################################
 # Get DNS database list from server

 do {
     $domains_done{$domain} = 1;
     delete $domains_waiting{$domain};

     $hostcnt = 0;
     $cnamecnt = 0;
     $lines = 0;
     $soa = 0;
     undef %host;
     undef %cname;
     undef %hostdata;

   dnsagain:
     debug(1, "Getting DNS database for $domain from server $server");
     open(DNS, "echo ls -d $domain | nslookup - $server 2>&1 |") ||
 	die "Error: Could not start nslookup to make dns list : $!\nError: Try giving --nslookup option and telling the path to nslookup program\n";

     while(<DNS>) {
 	$lines++;
 	chomp;
 	undef $hostname if/^\s*$/;
 	if (/^\s{0,1}([a-zA-Z0-9-]\S*)/) {
             $hostname = "\L$1\E";
 	}
 	next unless defined $hostname;
 	if (/^.*\s(SOA)\s+(.*)\s*$/ || $hostname eq "SOA") {
 	    undef $soa if(/^.*\s(SOA)\s+(.*)\s*$/);
 	    $data = $_ if ($hostname eq "SOA");
 	    $data = $2 unless $hostname eq "SOA";
 	    $data =~ s/\s*;.*$//;
 	    $data =~ s/^\s+//;
 	    if( defined $soa ) {
 		$soa .= " \L$data\E";
 	    } else {
 		$soa = "\L$data\E";
 	    }
 	    $hostname = "SOA";
         } elsif (/^.*\s(A|CNAME|NS)\s+(.*)\s*$/) {
             $host = $hostname;
 	    $field = "\L$1\E";
 	    $data = "\L$2\E";
 	    debug(70, "Line = /$host/$field/$data/");
 	    if ($host !~ /\.$/) {
 		$host .= ".$domain";
 	    } else {
 		$host =~ s/\.$//g;
 	    }
 	    if ($field eq "a") {
 		if ($host =~ /$domain$/) {
 		    if (defined($host{$host})) {
 			$host{$host} .= ",$data";
 		    } else {
 			$host{$host} = "$data";
 			$hostcnt++;
 		    }
 		    debug(30, "$host A == $host{$host}");
 		}
 	    } elsif ($field eq "cname") {
 		if ($data !~ /\.$/ && ! /^\s/ ) {
     		    $data .= ".$domain";
 	        } else {
 		    $data =~ s/\.$//g;
 	        }
 		if ($host =~ /$domain$/) {
 		    if (defined($cname{$data})) {
 			$cname{$data} .= ",$host";
 		    } else {
 			$cname{$data} = "$host";
 			$cnamecnt++;
 		    }
 		    debug(30, "$host CNAME $data");
 		    $junk = $data;
 		    $data = $host;
 		    $host = $junk;
 		}
 	    } elsif ($field eq "ns") {
 		if (!defined($domains_done{$host})) {
 		    if (!defined($domains_waiting{$host})) {
 			debug(10, "Adding subdomain $host to domains list, with NS $data");
 			$domains_waiting{$host} = $data;
 			push(@domains_waiting, $host);
 		    } else {
 			debug(10, "Adding NS $data for domain $host");
 			$domains_waiting{$host} .= ",$data";
 		    }
 		}
 	    }
 	    if (!defined($hostdata{$host})) {
 		$hostdata{$host} = "$host\n$field=$data\n";
 	    } else {
 		$hostdata{$host} .= "$field=$data\n";
 	    }
 	}
     }
     close(DNS);
     if ($hostcnt == 0 && $cnamecnt == 0) {
 	if ($#other_servers != -1) {
 	    $server = shift(@other_servers);
 	    goto dnsagain;
 	}
     }
     debug(1, "Found $hostcnt hosts, $cnamecnt CNAMEs (total $lines lines)");
     if (!defined($opt_keyscan)) {
 	print(STDOUT "#\n");
 	print(STDOUT "# Domain = $domain, server = $server\n");
 	print(STDOUT "# Found $hostcnt hosts, $cnamecnt CNAMEs (total $lines lines)\n");
 	print(STDOUT "# SOA = $soa\n");
 	print(STDOUT "#\n");
     }

 ######################################################################
 # Loop through hosts and try to connect to hosts

     foreach $i (sort (keys %host)) {
 	debug(50, "Host = $i, Hostdata = $hostdata{$i}");
 	if ($hostdata{$i} =~ /$grep_yes/im &&
 	    $hostdata{$i} !~ /$grep_no/im &&
 	    $i !~ /^localhost\./ &&
 	    $host{$i} !~ /^127.0.0.1$|^127.0.0.1,|,127.0.0.1$|,127.0.0.1,/) {
 	    debug(2, "Trying host $i");

 	    @hostnames = ();
 	    if (defined($cname{$i})) {
 		expand($i, \@hostnames, \@subdomains);
 		foreach $j (split(/,/, $cname{$i})) {
 		    expand($j, \@hostnames, \@subdomains);
 		}
 	    } else {
 		expand($i, \@hostnames, \@subdomains);
 	    }
 	    foreach $j (split(/,/, $host{$i})) {
 		push(@hostnames, $j);
 	    }
 	    $hostnames = join(',', (@hostnames));

 	    if (defined($opt_keyscan)) {
 		printf(STDOUT "$host{$i}\t$hostnames\n");
 	    } elsif (try_ping($i, $host{$i})) {
 		$trusted = 1;
 		$err = 'Timeout expired';
 		$ssh_key = try_ssh("$i");
 		if (!defined($ssh_key)) {
 		    $ssh_key = find_host_from_known_hosts($i);
 		    $trusted = 0;
 		}
 		if (defined($ssh_key)) {
 		    if ($trusted) {
 			debug(2, "Ssh to $i succeded");
 		    } else {
 			debug(2, "Ssh to $i failed, using local known_hosts entry");
 		    }
 		    debug(4, "adding entries : $hostnames");
 		    $ssh_key =~ s/root@//i;
 		    if (!$trusted && !$trustdaemon) {
 			print(STDOUT "# $hostnames $ssh_key\n");
 		    } else {
 			print(STDOUT "$hostnames $ssh_key\n");
 		    }
 		} else {
 		    debug(2, "ssh failed : $err");
 		}
 	    } else {
 		debug(2, "ping failed");
 	    }
 	} else {
 	    debug(10, "Skipped host $i");
 	}
     }
   again:
     $domain = shift(@domains_waiting);
     if (defined($domain)) {
 	$server = $domains_waiting{$domain};
 	@other_servers = split(',', $server);
 	$server = shift(@other_servers);
 	($server, @other_servers) = find_soa($domain, $server);
 	if(!defined($server)) {
 	    debug(1, "Skipping domain $domain because no DNS SOA entry found");
 	    $domains_done{$domain} = 1;
 	    delete $domains_waiting{$domain};
 	    goto again;
 	}
     }
 } while ($recursive && defined($domain));

 unlink($private_ssh_known_hosts);
 exit (0);

 ######################################################################
 # try_ping -- try to ping to host and return 1 if success
 # $success = try_ping($host, $list_ip_addrs);

 sub try_ping {
     my($host, $ipaddrs) = @_;
     my(@ipaddrs, $ipaddr, $serv, $ip);
     my($rin, $rout, $win, $wout, $nfound, $tmout, $buf, $len, $ret, $err);

     $buf = '';
     debug(51,"Trying to ping host $host");
     @ipaddrs = split(/,/, $ipaddrs);

     while ($ipaddr = shift(@ipaddrs)) {

 	debug(55,"Trying ipaddr $ipaddr");

 	#initialize socket
 	socket(PING, PF_INET, SOCK_STREAM, $tcpproto) ||
 	    die "socket failed : $!";
 	setsockopt(PING, SOL_SOCKET, SO_REUSEADDR, 1) ||
 	    die "setsockopt failed : $!";
 	PING->autoflush(1);
 	fcntl(PING, F_SETFL, fcntl(PING, F_GETFL, 0) | POSIX::O_NONBLOCK) ||
 	    die "fcntl failed : $!";

         $ip = pack('C4', split(/\./, $ipaddr, 4));
 	$serv = pack($sockaddr, AF_INET, $sshport, $ip);

       again:
 	# try connect
 	$ret = connect(PING, $serv);
 	$err = $!;
 	if (!$ret) {
 	    debug(60, "Connect failed : $err");
 	    if ($err == EINTR) {
 		goto again;
 	    }
 	    # socket not yet connected, wait for result, it will
 	    # wake up for writing when done
 	    $tmout = $ping_timeout;

  	    $rin = '';
 	    $win = '';
 	    vec($rin, fileno(PING), 1) = 1;
 	    vec($win, fileno(PING), 1) = 1;
 	    debug(60, "Waiting in select, rin = " . unpack('H*', $rin) .
 		  ", win = " . unpack('H*', $win));
 	    ($nfound) = select($rout = $rin, $wout = $win, undef, $tmout);
 	    $err = $!;
 	    debug(80, "Select returned $nfound, rout = " . unpack('H*', $rout) .
 		  ", wout = " . unpack('H*', $wout));
 	    if ($nfound != 0) {
 		# connect done, read the status with sysread
 		$ret = sysread(PING, $buf, 1);
 		$err = $!;
 		if (defined($ret) || $err == EAGAIN || $err == EWOULDBLOCK) {
 		    debug(60, "Select ok, read ok ($err), returning ok");
 		    # connection done, return ok
 		    shutdown(PING, 2);
 		    close(PING);
 		    return 1;
 		} else {
 		    # connection failed, try next ipaddr
 		    debug(60, "Select ok, read failed : $err, trying next");
 		    close(PING);
 		}
 	    } else {
 		# timeout exceeded, try next ipaddr
 		debug(60, "Select failed : $err, trying next");
 		close(PING);
 	    }
 	} else {
 	    # connect succeeded, return ok.
 	    debug(60, "Connect ok, returning ok");
 	    shutdown(PING, 2);
 	    close(PING);
 	    return 1;
 	}
     }
     debug(60, "Returning fail");
     return 0;
 }

 ######################################################################
 # try_ssh -- try ssh connection to host and return ssh_key if success
 # if failure return undef, and set $err string to contain error message.
 # $ssh_key = try_ssh($host);

 sub try_ssh {
     my($host) = @_;
     my($buf, $ret, $pos, $pid, $rin, $nfound, $tmout);

     $pid = open(SSH, "$ssh $host cat $public_key 2>&1 |");
     $err = undef;

     if ($pid == 0) {
 	$err = "could not open ssh connection to host";
 	return undef;
     }
     $ret = 1;
     $pos = 0;
     $buf = '';
     $tmout = $timeout;
     debug(10, "Starting ssh select loop");
   loop:
     while (1) {

 	$rin = '';
 	vec($rin, fileno(SSH), 1) = 1;
 	($nfound, $tmout) = select($rin, undef, undef, $tmout);

 	# Timeout
 	if ($nfound <= 0) {
 	    debug(20, "Ssh select timed out");
 	    kill(2, $pid); sleep(1); kill(9, $pid);
 	    close(SSH);
 	    $err = "Timeout expired";
 	    return undef;
 	}

 	$ret = sysread(SSH, $buf, 256, $pos);
 	# EOF or error
 	if ($ret <= 0) {
 	    # Yes, close the pipe and return
 	    close(SSH);
 	    debug(20, "Ssh select closed status = $?");
 	    $err = "No reply from ssh";
 	    return undef;
 	}
 	$pos += $ret;
 	while ($buf =~ /^(.*)\n\r?([\000-\377]*)$/) {
 	    $_ = $1;
 	    $buf = $2;
 	    $pos = length($buf);
 	    debug(20, "Ssh select loop, line = \"$_\"");
 	    if (/^connection.*refused/i) {
 		$err = "connection refused";
 	    } elsif (/^permission/i) {
 		$err = "permission denied";
 	    } elsif (/$public_key.*no\s+file/i) {
 		$err = "$public_key file not found";
 	    } elsif (/$public_key.*permission\s+denied/i) {
 		$err = "$public_key file permission denied";
 	    } elsif (/^\d+\s+\d+\s+\d/) {
 		kill(2, $pid); sleep(1); kill(9, $pid);
 		close(SSH);
 		return $_;
 	    }
 	    if (defined($err)) {
 		kill(2, $pid); sleep(1); kill(9, $pid);
 		close(SSH);
 		return undef;
 	    }
 	}
 	if ($buf =~ /password: $/i) {
 	    if (defined($passwordtimeout)) {
 		$tmout = $passwordtimeout;
 		print(STDERR "$bell\n\rPassword: ");
 		if ($tmout == 0) {
 		    $tmout = undef;
 		}
 	    } else {
 		$tmout = 0;
 	    }
 	    $buf = '';
 	    $pos = 0;
 	}
     }
 }

 ######################################################################
 # find_hosts_from_known_hosts -- find host key from private known_hosts file
 # $ssh_key = find_host_from_known_hosts($host);

 sub find_host_from_known_hosts {
     my($host) = @_;
     open(KNOWNHOSTS, "<$private_ssh_known_hosts") || return undef;
     while(<KNOWNHOSTS>) {
 	@_ = split(/\s+/, $_);
 	if ($_[0] =~ /^$host$|^$host,|,$host$/) {
 	    shift(@_);
 	    close(KNOWNHOSTS);
 	    return join(' ', @_);
 	}
     }
     close(KNOWNHOSTS);
     return undef;
 }

 ######################################################################
 # expand -- insert expanded hostnames to hostnames table
 # expand($hostname, \@hostnames, \@subdomains);

 sub expand {
     my($host, $hostnames, $subdomains) = @_;
     my($newhost, $sub, $entry);

     if (!$domainnamesplit) {
 	my(@domain_pieces);

 	# split domain to pieces
 	@domain_pieces = split(/\./, $host);

 	# add rest parts, except the one before full domain name
 	$entry = shift(@domain_pieces);

 	debug(20, "Adding autosplit entry $entry");
 	push(@$hostnames, $entry);

 	for(; $#domain_pieces > 1; ) {
 	    $entry .= "." . shift(@domain_pieces);
 	    debug(20, "Adding autosplit entry $entry");
 	    push(@$hostnames, $entry);
 	}
 	# add full domain name
 	debug(20, "Adding autosplit entry $host");
 	push(@$hostnames, $host);
     } else {
 	if ($host =~ /^(.*)$domain$/i) {
 	    $newhost = $1;
 	    $newhost =~ s/\.$//g;
 	    foreach $sub (@$subdomains) {
 		$entry = $newhost . $sub;
 		$entry =~ s/^\.//g;
 		if ($entry ne '') {
 		    debug(20, "Adding entry $entry");
 		    push(@$hostnames, $entry);
 		}
 	    }
 	}
     }
 }

 ######################################################################
 # Print debug text
 # debug(text_debug_level, string)

 sub debug {
     my($level, $str) = @_;
     if ($debug > $level) {
 	print(STDERR "$0:debug[$level]: $str\n");
     }
 }

 ######################################################################
 # find_soa -- find soa entry for domain
 # ($soa_origin, @other_servers) = find_soa($domain, $initial_server)

 sub find_soa {
     my($domain, $initial_server) = @_;
     my($field, $data, $server, @other_servers);

     open(DNS, "$nslookup -type=soa $domain $initial_server 2>&1 |") ||
 	die "Error: Could not start nslookup to find SOA entry for $domain : $!\nError: Try giving the path to it with --nslookup option\n";

     while (<DNS>) {
 	if (/^[^=]*origin\s*=\s*(.*)/) {
 	    $server = $1;
 	    debug(10, "Found origin : $1");
 	} elsif (/^[^=]*nameserver\s*=\s*(.*)\s*$/) {
 	    push(@other_servers, $1);
 	    debug(10, "Found nameserver : $1");
 	}
     }
     close(DNS);
     return($server, @other_servers);
 }

 ######################################################################
 # make_perl_happy -- use some symbols, so perl doesn't complain so much
 # make_perl_happy();

 sub make_perl_happy {
     if (0) {
 	print $opt_silent;
     }
 }

 1;
	#!/usr/bin/perl -w
	# -- perl --
	######################################################################
	# make-ssh-known-hosts.pl -- Make ssh-known-hosts file
	# Copyright (c) 1995 Tero Kivinen
	# All Rights Reserved.
	#
	# Make-ssh-known-hosts is distributed in the hope that it will be
	# useful, but WITHOUT ANY WARRANTY. No author or distributor accepts
	# responsibility to anyone for the consequences of using it or for
	# whether it serves any particular purpose or works at all, unless he
	# says so in writing. Refer to the GNU General Public License for full
	# details.
	#
	# Everyone is granted permission to copy, modify and redistribute
	# make-ssh-known-hosts, but only under the conditions described in
	# the GNU General Public License. A copy of this license is supposed to
	# have been given to you along with make-ssh-known-hosts so you can
	# know your rights and responsibilities. It should be in a file named
	# gnu-COPYING-GPL. Among other things, the copyright notice and this notice
	# must be preserved on all copies.
	######################################################################
	# Program: make-ssh-known-hosts.pl
	# $Source: /var/cvs/openssh/contrib/Attic/make-ssh-known-hosts.pl,v $
	# Author : $Author: damien $
	#
	# (C) Tero Kivinen 1995 <Tero.Kivinen@hut.fi>
	#
	# Creation : 19:52 Jun 27 1995 kivinen
	# Last Modification : 00:07 Jul 8 1998 kivinen
	# Last check in : $Date: 2000/03/15 01:13:03 $
	# Revision number : $Revision: 1.1 $
	# State : $State: Exp $
	# Version : 1.343
	# Edit time : 242 min
	#
	# Description : Make ssh-known-host file from dns data.
	#
	# $Log: make-ssh-known-hosts.pl,v $
	# Revision 1.1 2000/03/15 01:13:03 damien
	# - Created contrib/ subdirectory. Included helpers from Phil Hands'
	# Debian package, README file and chroot patch from Ricardo Cerqueira
	# <rmcc@clix.pt>
	# - Moved gnome-ssh-askpass.c to contrib directory and reomved config
	# option.
	# - Slight cleanup to doc files
	#
	# Revision 1.6 1998/07/08 00:44:23 kivinen
	# Fixed to understand bind 8 nslookup output.
	#
	# Revision 1.5 1998/04/30 01:53:33 kivinen
	# Moved kill before close and added sending SIGINT first and
	# then 1 second sleep before sending SIGKILL.
	#
	# Revision 1.4 1998/04/17 00:39:19 kivinen
	# Changed to close ssh program filedescriptor before killing it.
	# Removed ^ from the password matching prompt.
	#
	# Revision 1.3 1997/04/17 04:21:27 kivinen
	# Changed to use 3des by default.
	#
	# Revision 1.2 1997/03/26 07:14:01 kivinen
	# Added EWOULDBLOCK.
	#
	# Revision 1.1.1.1 1996/02/18 21:38:10 ylo
	# Imported ssh-1.2.13.
	#
	# Revision 1.4 1995/10/02 01:23:45 ylo
	# Ping packet size fixes from Kivinen.
	#
	# Revision 1.3 1995/08/29 22:37:39 ylo
	# Now uses GlobalKnownHostsFile and UserKnownHostsFile.
	#
	# Revision 1.2 1995/07/15 13:26:37 ylo
	# Changes from kivinen.
	#
	# Revision 1.1.1.1 1995/07/12 22:41:05 ylo
	# Imported ssh-1.0.0.
	#
	#
	#
	# If you have any useful modifications or extensions please send them to
	# Tero.Kivinen@hut.fi
	#
	######################################################################
	# initialization

	require 5.000;
	use Getopt::Long;
	use FileHandle;
	use POSIX;
	use Socket;
	use Fcntl;

	$version = ' $Id: make-ssh-known-hosts.pl,v 1.1 2000/03/15 01:13:03 damien Exp $ ';

	$command_line = "$0 ";
	foreach $a (@ARGV) {
	$command_line .= $a . " ";
	}
	STDERR->autoflush(1);

	######################################################################
	# default values for options

	$debug = 5;
	$defserver = '';
	$bell='\a';
	$public_key = '/etc/ssh_host_key.pub';
	$private_ssh_known_hosts = "/tmp/ssh_known_hosts$$";
	$timeout = 60;
	$ping_timeout = 3;
	$passwordtimeout = undef;
	$trustdaemon = 1;
	$domainnamesplit = 0;
	$recursive = 1;

	######################################################################
	# Programs and their options

	$nslookup = "nslookup";

	$ssh="ssh -a -c 3des -x -o 'ConnectionAttempts 1' -o 'FallBackToRsh no' -o 'GlobalKnownHostsFile /dev/null' -o 'KeepAlive yes' -o 'StrictHostKeyChecking no' -o 'UserKnownHostsFile $private_ssh_known_hosts'";
	$sshdisablepasswordoption="-o 'BatchMode yes' -o 'PasswordAuthentication no'";

	######################################################################
	# Cleanup and initialization

	unlink($private_ssh_known_hosts);
	$sockaddr = 'S n a4 x8';
	($junk, $junk, $sshport) = getservbyname("ssh", "tcp");
	if (!defined($sshport)) {
	$sshport = 22;
	}
	($tcpprotoname, $junk, $tcpproto) = getprotobyname('tcp');
	defined($tcpprotoname) \|\| die "getprotobyname : $!";

	######################################################################
	# Parse options

	GetOptions("initialdns=s", "server=s", "subdomains=s",
	"debug=i", "timeout=i", "passwordtimeout=i",
	"trustdaemon!", "domainnamesplit", "silent",
	"nslookup=s", "pingtimeout=i", "recursive!",
	"keyscan",
	"ssh=s")
	\|\| die "Getopt : $!";

	if (defined($opt_initialdns)) { $defserver = $opt_initialdns; }

	if (defined($opt_server)) { $server = $opt_server; }

	if (defined($opt_subdomains)) { @subdomains = split(/,/, $opt_subdomains); }

	if (defined($opt_debug)) { $debug = $opt_debug; }

	if (defined($opt_timeout)) { $timeout = $opt_timeout; }

	if (defined($opt_pingtimeout)) { $ping_timeout = $opt_pingtimeout; }

	if (defined($opt_passwordtimeout)) {
	$passwordtimeout = $opt_passwordtimeout;
	$sshdisablepasswordoption = '';
	}

	if (defined($opt_trustdaemon)) { $trustdaemon = $opt_trustdaemon; }

	if (defined($opt_recursive)) { $recursive = $opt_recursive; }

	if (defined($opt_domainnamesplit)) { $domainnamesplit = $opt_domainnamesplit; }

	if (defined($opt_silent)) { $bell = ''; }

	if (defined($opt_nslookup)) { $nslookup = $opt_nslookup; }

	if (defined($opt_ssh)) { $ssh = $opt_ssh; } else {
	$ssh = "$ssh $sshdisablepasswordoption";
	}

	if ($#ARGV == 0) {
	$domain = "\L$ARGV[0]\E";
	$grep_yes = '.*';
	$grep_no = '^$';
	} elsif ($#ARGV == 1) {
	$domain = "\L$ARGV[0]\E";
	$grep_yes = $ARGV[1];
	$grep_no = '^$';
	} elsif ($#ARGV == 2) {
	$domain = "\L$ARGV[0]\E";
	$grep_yes = $ARGV[1];
	$grep_no = $ARGV[2];
	} else {
	print(STDERR "$0 [--initialdns initial_dns_server] [--server dns_server] [--subdomains sub.sub.domain,sub.sub,sub,] [--debug debug_level] [--timeout ssh_exec_timeout_in_secs] [--pingtimeout ping_timeout_in_secs] [--passwordtimeout timeout_for_password_in_secs] [--notrustdaemon] [--norecursive] [--domainnamesplit] [--silent] [--keyscan] [--nslookup path_to_nslookup] [--ssh path_to_ssh] full.domain [ host_info_take_regexp [ host_info_remove_regex ]]\n");
	exit(1);
	}

	######################################################################
	# Check that ssh program exists

	if (system("$ssh > /dev/null 2>&1 ") != 256) {
	print(STDERR "Error: Could not run ssh program ($ssh): $!\nError: Try giving the path to it with --ssh option\n");
	exit(1);
	}

	######################################################################
	# Generate subdomains list

	if (!$domainnamesplit) {
	debug(6, "Auto splitting host entries");
	} elsif (!defined(@subdomains)) {
	debug(6, "Generating subdomain list");

	# split domain to pieces
	@domain_pieces = split(/\./, $domain);

	# add empty domain part
	push(@subdomains, '');

	# add rest parts, except the one before full domain name
	$entry='';
	for(; $#domain_pieces > 1; ) {
	$entry .= "." . shift(@domain_pieces);
	push(@subdomains, $entry);
	}

	# add full domain name
	push(@subdomains, ".$domain");
	debug(5, "Subdomain list: " . join(',', @subdomains));
	} else {
	debug(5, "Using given subdomain list:" . join(',', @subdomains));
	}

	######################################################################
	# finding SOA entry for domain

	@other_servers = ();
	if (!defined($server)) {
	debug(6, "Finding DNS database SOA entry");

	($server, @other_servers) = find_soa($domain, $defserver);

	if (!defined($server)) {
	print(STDERR "Error: Could not find DNS SOA entry from default dns server\nError: Try giving the initial nameserver with --initialdns option\n");
	exit(1);
	} else {
	debug(5, "DNS server found : $server");
	}
	} else {
	debug(5, "Using given DNS server : $server");
	}

	######################################################################
	# Print header

	($name, $junk, $junk, $junk, $junk, $junk, $gecos) = getpwuid($<);
	$gecos =~ s/,.*$//g;

	if (!defined($opt_keyscan)) {
	print(STDOUT "# This file is generated with make-ssh-known-hosts.pl\n");
	print(STDOUT "#$version\n");
	print(STDOUT "# with command line :\n");
	print(STDOUT "# $command_line\n");
	print(STDOUT "#\n");
	print(STDOUT "# The script was run by $gecos ($name) at " . localtime() . "\n");
	print(STDOUT "# using perl ($^X) version $].\n");
	}

	######################################################################
	# Get DNS database list from server

	do {
	$domains_done{$domain} = 1;
	delete $domains_waiting{$domain};

	$hostcnt = 0;
	$cnamecnt = 0;
	$lines = 0;
	$soa = 0;
	undef %host;
	undef %cname;
	undef %hostdata;

	dnsagain:
	debug(1, "Getting DNS database for $domain from server $server");
	open(DNS, "echo ls -d $domain \| nslookup - $server 2>&1 \|") \|\|
	die "Error: Could not start nslookup to make dns list : $!\nError: Try giving --nslookup option and telling the path to nslookup program\n";

	while(<DNS>) {
	$lines++;
	chomp;
	undef $hostname if/^\s*$/;
	if (/^\s{0,1}([a-zA-Z0-9-]\S*)/) {
	$hostname = "\L$1\E";
	}
	next unless defined $hostname;
	if (/^.\s(SOA)\s+(.)\s*$/ \|\| $hostname eq "SOA") {
	undef $soa if(/^.\s(SOA)\s+(.)\s*$/);
	$data = $_ if ($hostname eq "SOA");
	$data = $2 unless $hostname eq "SOA";
	$data =~ s/\s;.$//;
	$data =~ s/^\s+//;
	if( defined $soa ) {
	$soa .= " \L$data\E";
	} else {
	$soa = "\L$data\E";
	}
	$hostname = "SOA";
	} elsif (/^.\s(A\|CNAME\|NS)\s+(.)\s*$/) {
	$host = $hostname;
	$field = "\L$1\E";
	$data = "\L$2\E";
	debug(70, "Line = /$host/$field/$data/");
	if ($host !~ /\.$/) {
	$host .= ".$domain";
	} else {
	$host =~ s/\.$//g;
	}
	if ($field eq "a") {
	if ($host =~ /$domain$/) {
	if (defined($host{$host})) {
	$host{$host} .= ",$data";
	} else {
	$host{$host} = "$data";
	$hostcnt++;
	}
	debug(30, "$host A == $host{$host}");
	}
	} elsif ($field eq "cname") {
	if ($data !~ /\.$/ && ! /^\s/ ) {
	$data .= ".$domain";
	} else {
	$data =~ s/\.$//g;
	}
	if ($host =~ /$domain$/) {
	if (defined($cname{$data})) {
	$cname{$data} .= ",$host";
	} else {
	$cname{$data} = "$host";
	$cnamecnt++;
	}
	debug(30, "$host CNAME $data");
	$junk = $data;
	$data = $host;
	$host = $junk;
	}
	} elsif ($field eq "ns") {
	if (!defined($domains_done{$host})) {
	if (!defined($domains_waiting{$host})) {
	debug(10, "Adding subdomain $host to domains list, with NS $data");
	$domains_waiting{$host} = $data;
	push(@domains_waiting, $host);
	} else {
	debug(10, "Adding NS $data for domain $host");
	$domains_waiting{$host} .= ",$data";
	}
	}
	}
	if (!defined($hostdata{$host})) {
	$hostdata{$host} = "$host\n$field=$data\n";
	} else {
	$hostdata{$host} .= "$field=$data\n";
	}
	}
	}
	close(DNS);
	if ($hostcnt == 0 && $cnamecnt == 0) {
	if ($#other_servers != -1) {
	$server = shift(@other_servers);
	goto dnsagain;
	}
	}
	debug(1, "Found $hostcnt hosts, $cnamecnt CNAMEs (total $lines lines)");
	if (!defined($opt_keyscan)) {
	print(STDOUT "#\n");
	print(STDOUT "# Domain = $domain, server = $server\n");
	print(STDOUT "# Found $hostcnt hosts, $cnamecnt CNAMEs (total $lines lines)\n");
	print(STDOUT "# SOA = $soa\n");
	print(STDOUT "#\n");
	}

	######################################################################
	# Loop through hosts and try to connect to hosts

	foreach $i (sort (keys %host)) {
	debug(50, "Host = $i, Hostdata = $hostdata{$i}");
	if ($hostdata{$i} =~ /$grep_yes/im &&
	$hostdata{$i} !~ /$grep_no/im &&
	$i !~ /^localhost\./ &&
	$host{$i} !~ /^127.0.0.1$\|^127.0.0.1,\|,127.0.0.1$\|,127.0.0.1,/) {
	debug(2, "Trying host $i");

	@hostnames = ();
	if (defined($cname{$i})) {
	expand($i, \@hostnames, \@subdomains);
	foreach $j (split(/,/, $cname{$i})) {
	expand($j, \@hostnames, \@subdomains);
	}
	} else {
	expand($i, \@hostnames, \@subdomains);
	}
	foreach $j (split(/,/, $host{$i})) {
	push(@hostnames, $j);
	}
	$hostnames = join(',', (@hostnames));

	if (defined($opt_keyscan)) {
	printf(STDOUT "$host{$i}\t$hostnames\n");
	} elsif (try_ping($i, $host{$i})) {
	$trusted = 1;
	$err = 'Timeout expired';
	$ssh_key = try_ssh("$i");
	if (!defined($ssh_key)) {
	$ssh_key = find_host_from_known_hosts($i);
	$trusted = 0;
	}
	if (defined($ssh_key)) {
	if ($trusted) {
	debug(2, "Ssh to $i succeded");
	} else {
	debug(2, "Ssh to $i failed, using local known_hosts entry");
	}
	debug(4, "adding entries : $hostnames");
	$ssh_key =~ s/root@//i;
	if (!$trusted && !$trustdaemon) {
	print(STDOUT "# $hostnames $ssh_key\n");
	} else {
	print(STDOUT "$hostnames $ssh_key\n");
	}
	} else {
	debug(2, "ssh failed : $err");
	}
	} else {
	debug(2, "ping failed");
	}
	} else {
	debug(10, "Skipped host $i");
	}
	}
	again:
	$domain = shift(@domains_waiting);
	if (defined($domain)) {
	$server = $domains_waiting{$domain};
	@other_servers = split(',', $server);
	$server = shift(@other_servers);
	($server, @other_servers) = find_soa($domain, $server);
	if(!defined($server)) {
	debug(1, "Skipping domain $domain because no DNS SOA entry found");
	$domains_done{$domain} = 1;
	delete $domains_waiting{$domain};
	goto again;
	}
	}
	} while ($recursive && defined($domain));

	unlink($private_ssh_known_hosts);
	exit (0);

	######################################################################
	# try_ping -- try to ping to host and return 1 if success
	# $success = try_ping($host, $list_ip_addrs);

	sub try_ping {
	my($host, $ipaddrs) = @_;
	my(@ipaddrs, $ipaddr, $serv, $ip);
	my($rin, $rout, $win, $wout, $nfound, $tmout, $buf, $len, $ret, $err);

	$buf = '';
	debug(51,"Trying to ping host $host");
	@ipaddrs = split(/,/, $ipaddrs);

	while ($ipaddr = shift(@ipaddrs)) {

	debug(55,"Trying ipaddr $ipaddr");

	#initialize socket
	socket(PING, PF_INET, SOCK_STREAM, $tcpproto) \|\|
	die "socket failed : $!";
	setsockopt(PING, SOL_SOCKET, SO_REUSEADDR, 1) \|\|
	die "setsockopt failed : $!";
	PING->autoflush(1);
	fcntl(PING, F_SETFL, fcntl(PING, F_GETFL, 0) \| POSIX::O_NONBLOCK) \|\|
	die "fcntl failed : $!";

	$ip = pack('C4', split(/\./, $ipaddr, 4));
	$serv = pack($sockaddr, AF_INET, $sshport, $ip);

	again:
	# try connect
	$ret = connect(PING, $serv);
	$err = $!;
	if (!$ret) {
	debug(60, "Connect failed : $err");
	if ($err == EINTR) {
	goto again;
	}
	# socket not yet connected, wait for result, it will
	# wake up for writing when done
	$tmout = $ping_timeout;

	$rin = '';
	$win = '';
	vec($rin, fileno(PING), 1) = 1;
	vec($win, fileno(PING), 1) = 1;
	debug(60, "Waiting in select, rin = " . unpack('H*', $rin) .
	", win = " . unpack('H*', $win));
	($nfound) = select($rout = $rin, $wout = $win, undef, $tmout);
	$err = $!;
	debug(80, "Select returned $nfound, rout = " . unpack('H*', $rout) .
	", wout = " . unpack('H*', $wout));
	if ($nfound != 0) {
	# connect done, read the status with sysread
	$ret = sysread(PING, $buf, 1);
	$err = $!;
	if (defined($ret) \|\| $err == EAGAIN \|\| $err == EWOULDBLOCK) {
	debug(60, "Select ok, read ok ($err), returning ok");
	# connection done, return ok
	shutdown(PING, 2);
	close(PING);
	return 1;
	} else {
	# connection failed, try next ipaddr
	debug(60, "Select ok, read failed : $err, trying next");
	close(PING);
	}
	} else {
	# timeout exceeded, try next ipaddr
	debug(60, "Select failed : $err, trying next");
	close(PING);
	}
	} else {
	# connect succeeded, return ok.
	debug(60, "Connect ok, returning ok");
	shutdown(PING, 2);
	close(PING);
	return 1;
	}
	}
	debug(60, "Returning fail");
	return 0;
	}

	######################################################################
	# try_ssh -- try ssh connection to host and return ssh_key if success
	# if failure return undef, and set $err string to contain error message.
	# $ssh_key = try_ssh($host);

	sub try_ssh {
	my($host) = @_;
	my($buf, $ret, $pos, $pid, $rin, $nfound, $tmout);

	$pid = open(SSH, "$ssh $host cat $public_key 2>&1 \|");
	$err = undef;

	if ($pid == 0) {
	$err = "could not open ssh connection to host";
	return undef;
	}
	$ret = 1;
	$pos = 0;
	$buf = '';
	$tmout = $timeout;
	debug(10, "Starting ssh select loop");
	loop:
	while (1) {

	$rin = '';
	vec($rin, fileno(SSH), 1) = 1;
	($nfound, $tmout) = select($rin, undef, undef, $tmout);

	# Timeout
	if ($nfound <= 0) {
	debug(20, "Ssh select timed out");
	kill(2, $pid); sleep(1); kill(9, $pid);
	close(SSH);
	$err = "Timeout expired";
	return undef;
	}

	$ret = sysread(SSH, $buf, 256, $pos);
	# EOF or error
	if ($ret <= 0) {
	# Yes, close the pipe and return
	close(SSH);
	debug(20, "Ssh select closed status = $?");
	$err = "No reply from ssh";
	return undef;
	}
	$pos += $ret;
	while ($buf =~ /^(.)\n\r?([\000-\377])$/) {
	$_ = $1;
	$buf = $2;
	$pos = length($buf);
	debug(20, "Ssh select loop, line = \"$_\"");
	if (/^connection.*refused/i) {
	$err = "connection refused";
	} elsif (/^permission/i) {
	$err = "permission denied";
	} elsif (/$public_key.*no\s+file/i) {
	$err = "$public_key file not found";
	} elsif (/$public_key.*permission\s+denied/i) {
	$err = "$public_key file permission denied";
	} elsif (/^\d+\s+\d+\s+\d/) {
	kill(2, $pid); sleep(1); kill(9, $pid);
	close(SSH);
	return $_;
	}
	if (defined($err)) {
	kill(2, $pid); sleep(1); kill(9, $pid);
	close(SSH);
	return undef;
	}
	}
	if ($buf =~ /password: $/i) {
	if (defined($passwordtimeout)) {
	$tmout = $passwordtimeout;
	print(STDERR "$bell\n\rPassword: ");
	if ($tmout == 0) {
	$tmout = undef;
	}
	} else {
	$tmout = 0;
	}
	$buf = '';
	$pos = 0;
	}
	}
	}

	######################################################################
	# find_hosts_from_known_hosts -- find host key from private known_hosts file
	# $ssh_key = find_host_from_known_hosts($host);

	sub find_host_from_known_hosts {
	my($host) = @_;
	open(KNOWNHOSTS, "<$private_ssh_known_hosts") \|\| return undef;
	while(<KNOWNHOSTS>) {
	@_ = split(/\s+/, $_);
	if ($_[0] =~ /^$host$\|^$host,\|,$host$/) {
	shift(@_);
	close(KNOWNHOSTS);
	return join(' ', @_);
	}
	}
	close(KNOWNHOSTS);
	return undef;
	}

	######################################################################
	# expand -- insert expanded hostnames to hostnames table
	# expand($hostname, \@hostnames, \@subdomains);

	sub expand {
	my($host, $hostnames, $subdomains) = @_;
	my($newhost, $sub, $entry);

	if (!$domainnamesplit) {
	my(@domain_pieces);

	# split domain to pieces
	@domain_pieces = split(/\./, $host);

	# add rest parts, except the one before full domain name
	$entry = shift(@domain_pieces);

	debug(20, "Adding autosplit entry $entry");
	push(@$hostnames, $entry);

	for(; $#domain_pieces > 1; ) {
	$entry .= "." . shift(@domain_pieces);
	debug(20, "Adding autosplit entry $entry");
	push(@$hostnames, $entry);
	}
	# add full domain name
	debug(20, "Adding autosplit entry $host");
	push(@$hostnames, $host);
	} else {
	if ($host =~ /^(.*)$domain$/i) {
	$newhost = $1;
	$newhost =~ s/\.$//g;
	foreach $sub (@$subdomains) {
	$entry = $newhost . $sub;
	$entry =~ s/^\.//g;
	if ($entry ne '') {
	debug(20, "Adding entry $entry");
	push(@$hostnames, $entry);
	}
	}
	}
	}
	}

	######################################################################
	# Print debug text
	# debug(text_debug_level, string)

	sub debug {
	my($level, $str) = @_;
	if ($debug > $level) {
	print(STDERR "$0:debug[$level]: $str\n");
	}
	}

	######################################################################
	# find_soa -- find soa entry for domain
	# ($soa_origin, @other_servers) = find_soa($domain, $initial_server)

	sub find_soa {
	my($domain, $initial_server) = @_;
	my($field, $data, $server, @other_servers);

	open(DNS, "$nslookup -type=soa $domain $initial_server 2>&1 \|") \|\|
	die "Error: Could not start nslookup to find SOA entry for $domain : $!\nError: Try giving the path to it with --nslookup option\n";

	while (<DNS>) {
	if (/^[^=]origin\s=\s(.)/) {
	$server = $1;
	debug(10, "Found origin : $1");
	} elsif (/^[^=]nameserver\s=\s(.)\s*$/) {
	push(@other_servers, $1);
	debug(10, "Found nameserver : $1");
	}
	}
	close(DNS);
	return($server, @other_servers);
	}

	######################################################################
	# make_perl_happy -- use some symbols, so perl doesn't complain so much
	# make_perl_happy();

	sub make_perl_happy {
	if (0) {
	print $opt_silent;
	}
	}

	1;