#!/usr/bin/perl -w
# 
# smb2lmhost.pl
#
#   Author:       Heiko Teichmeier
#                 Glauchau/Sa., Germany
#   E-Mail:       heiko@tei-lin-net.de
#   Web:          www.tei-lin-net.de
#
#   Date:         2004-03-14
#   Version:      0.1.5
#   License:      GPL
#
#   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)
#   2004-03-06 v. 0.1.3
#   2004-03-14 v. 0.1.4 (set the script under GPL-Licence)
#   2004-03-14 v. 0.1.5 (modify the script to sort the machine-/ip-pairs)
#

use strict;

my $VERSION = "0.1.5";

#=== 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";
my $lm_tmp_m  = "/etc/samba/lmhosts.tmp_m";
my $lm_tmp_i  = "/etc/samba/lmhosts.tmp_i";
my $lm_tmp1   = "/etc/samba/lmhosts.tmp1";
my $lm_tmp2   = "/etc/samba/lmhosts.tmp2";
my $lm_tmp3   = "/etc/samba/lmhosts.tmp3";

# 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 - collecting machine-/ip-pairs over a long time, all old
# pairs are inserted in the new lmhost-file too
my $lm_read_old = 1;

my $smbstatus   = "/usr/bin/smbstatus";
my $proid       = 0;
my $mach_name   = "";
my $mach_ip     = "";

# here you can set a criterium to sort the machine/ip-pairs;
#    "ip"   sort by ip-adresses
#    "name" sort by machine-names
#           as default we use the ip-adress sorting
my $sort_crit   = "ip";
#
#=== end of definitions ================

my (%machines,@clients,@message,$client,@mach_names,@proc_ids);
my ($strn_tmp,$strn_1,$strn_2);
my (@pairs_m,@pairs_i,@sort_pairs_m,@sort_pairs_i,@save_rows,@sort_pairs);
my (@sort_pairs_mt,@sort_pairs_it,@str_tmp);
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];
	    # delete the last char - is the newline-char
	    chomp $value;
    	    $machines{$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];

	# store length of the string "machine-ip", to 
	# cut the "(" and ")"
	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 as strings to various arrays
foreach my $key (keys %machines) {
    $strn_1 = "$key|$machines{$key}";
    @pairs_i = (@pairs_i,$strn_1);
    $strn_2 = "$machines{$key}|$key";
    @pairs_m = (@pairs_m,$strn_2);
}

@sort_pairs_mt = sort @pairs_m;
@sort_pairs_it = sort @pairs_i;

$strn_tmp = "";
while(@sort_pairs_mt) {
    $strn_tmp = shift(@sort_pairs_mt);
    @str_tmp  = split(/\|/,$strn_tmp);
    $strn_tmp = "$str_tmp[1]\t$str_tmp[0]";
    @sort_pairs_m = (@sort_pairs_m,$strn_tmp);
} 

$strn_tmp = "";
while(@sort_pairs_it) {
    $strn_tmp = shift(@sort_pairs_it);
    @str_tmp  = split(/\|/, $strn_tmp);
    $strn_tmp = "$str_tmp[0]\t$str_tmp[1]";
    @sort_pairs_i = (@sort_pairs_i,$strn_tmp);
} 

# write NULL string and then the array @sort_pairs to $lm_file
open(WRFILE, ">$lm_file") || die "Open of \$lm_file failed!.\n$!\n";
    printf WRFILE "";
    if ($write_msg) {
		printf WRFILE "$lm_msg";
    }
	# set the array "@sort_pairs" to the selected one
	if ($sort_crit eq "name")  {@sort_pairs = @sort_pairs_m;}
	elsif ($sort_crit eq "ip") {@sort_pairs = @sort_pairs_i;}
	else {@sort_pairs = @sort_pairs_i;}

	    while(@sort_pairs) {
    		my $row = shift(@sort_pairs);
    		printf WRFILE "$row\n";
	    }
close(WRFILE);


exit 0;