#!/usr/bin/perl -w
# 
#@(#) smb2lmhost.pl Description:
#@(#) A perl script which allows you collect the windows machine names
#@(#) with the corresponding IP adress (IPv4 only) using
#@(#) the 'smbstatus' command.
#@(#) It should write these pairs to the file "lmhosts", because other 
#@(#) scripts are functional only if the machine-name/IP mapping 
#@(#) works fine.
#@(#)  Based on the script "smb-wall.pl" by Keith Farrar
#@(#)  <farrar@parc.xerox.com>
#
#=============================================================================
#
# Modified by
#   Heiko Teichmeier <heiko@tei-lin-net.de>
#   2003-11-19 v. 0.0.1
#   2003-11-20 v. 0.1.1
#   
#   2004-02-25 v. 0.1.2 (with help by Peter Reinhart, correct my bad english, thanks to him)
#
#   Glauchau/Sa., Germany
#

use strict;

#=== definitions of your environment ===
#
# location and name of the lmhost-file
my $lm_file   = "/etc/samba/lmhosts";
# location and name of safety-copy of the original lmhost-file
my $lm_backup = "/etc/samba/lmhosts.orig";
# location and name of the temporarily changed lmhost-file
my $lm_tmp    = "/etc/samba/lmhosts.tmp";

# write to the 'lmhosts' file - yes=1, no=0 or nothing
my $lm_write  = 1;

# write the message-header to the lmhosts-file - yes=1, no=0 or nothing
my $write_msg = 1;

# create the 'lmhosts' file if not existing - yes=1, no=0 or nothing
my $lm_create = 1;

my $dat = localtime(time);

# a message to write to the begin of the lmhosts-file to let the user know 
# how the file hase been created
# the user should know, that a bad user, who use a faked IP adress, would through this
# script automatically push to the 'lmhosts' file!
my $lm_msg  = "# \n";
   $lm_msg .= "# This 'lmhosts' file whas automatically generated by\n";
   $lm_msg .= "# the $0-Script\n";
   $lm_msg .= "#              +---------------------------+\n";
   $lm_msg .= "# last run on: \| $dat \n";
   $lm_msg .= "#              +---------------------------+\n";
   $lm_msg .= "# The Windows name/IP adress pairs are based on calls from\n";
   $lm_msg .= "# the 'smbstatus' script\n";
   $lm_msg .= "# \n";

# read the name-IP-pairs from the original lmhosts-file to insert in the 
# new created file
my $lm_read_old = 1;

my $smbstatus   = "/usr/bin/smbstatus";
my $proid       = 0;
my $mach_name   = "";
my $mach_ip     = "";
#
#=== end of definitions ================

my (%machines,@clients,@message,$client,@mach_names,@proc_ids,@save_rows);
my $count   = 0;
my $lm_miss = 0;

# test - does the "lmhosts" file already exist?
if (! -e $lm_file) {
		print "File \'$lm_file\' not found!\n";
		$lm_miss = "1";
		if (not ($lm_create eq 1)) {
			print "\'$lm_file\' creation not wish!\n";
			print "See options in the script!\n\n";
			exit 1;
		}
}
else {
    open(RDFILE, "<$lm_file") || die "Open of \$lm_file failed!.\n$!\n";
	while(<RDFILE>) {
	    my $inp   = $_;
	    $count++;
	    # saving the rows of the file to the array '@save_rows'
	    my $anz = push(@save_rows,$inp);
	    # rows select - no comments, no space or NULL rows
	    # leere und Kommentar-Zeilen ueberspringen
	    next if $inp =~ /^\#/;
	    next if $inp =~ /^$/;
	    next if $inp =~ /^ /;
	    next unless $inp =~ /^[0-9]+/;
	    my @data = split(' ', $inp, 2);
		# do not accept this line if it consists of less then two fields
		next unless $data[1];
	    my $key = $data[0];
	    my $value = $data[1];
    	    $machines{$key} = $value;
	}
    close(RDFILE);
}


# save the rows of the $lm_file to the $lm_backup-file
open(WRFILE, ">$lm_backup") || die "Open of \$lm_backup failed!.\n$!\n";
    while(@save_rows) {
        my $row = shift(@save_rows);
        printf WRFILE $row;
    }
close(WRFILE);


# call 'smbstatus' to look for Windows client name/IP adress pairs
open(PCLIST, "$smbstatus |") || die "$smbstatus failed!.\n$!\n";
    while(<PCLIST>) {
		last if /^Locked files:/;
		my @arr	= split(" ", $_, 6);
		# do not accept this line if it consists of less than six fields
		next unless $arr[5];

		# Reads out and saves PID
		# PID auslesen und speichern
		$proid = $arr[3];
		push(@proc_ids, $proid);

		$client = $arr[4];
		next unless $client =~ /[^.]/;       # expect 'dot' in a client name
		next if grep($_ eq $client, @clients); # we only want this name once
		push (@clients,$client);

		# Reads and stores machine name/IP adress raw
		my $mach_ip_raw = $arr[5];
		my @ip_arr      = split(" ", $mach_ip_raw, 6);
		my $mach_ip_raw1= $ip_arr[0];
		my $len         = length $mach_ip_raw1;
		my $mach_ip     = substr($mach_ip_raw1, 1, $len-2);
		$machines{$mach_ip}=$client;
    }
    if ($lm_miss) {
		$machines{"127.0.0.1"}="localhost";
}
close(PCLIST);


# write the key pairs from the hash %machines to tmp-file
if (not open(WRFILE, ">$lm_tmp")) {
    die "Open of \$lm_tmp failed!.\n$!\n";
    }
else {
    if ($write_msg) {
		printf WRFILE "$lm_msg";
	}
	foreach my $key (keys %machines) {
	    printf WRFILE "$key\t$machines{$key}\n";
	}
    close(WRFILE);
}


# read the comlete $lm_tmp file in the array @save_rows
@save_rows = "";
my $row    = "";
open(RDFILE, "<$lm_tmp") || die "Open of \$lm_file failed!.\n$!\n";
    while(<RDFILE>) {
        $row = $_;
	my $anz = push(@save_rows,$row);
    }
close(RDFILE);


# write NULL string and then the array @save_rows to $lm_file
open(WRFILE, ">$lm_file") || die "Open of \$lm_file failed!.\n$!\n";
    printf WRFILE "";
    while(@save_rows) {
        my $row = shift(@save_rows);
        printf WRFILE $row;
    }
close(WRFILE);


exit 0;