#!/usr/bin/perl -w
# A script that imports text arptables rules. Similar to iptables-restore.

use strict;
my $tool = "/sbin/arptables";
my $table;
my $rc;
my $line;

# ==============================
# clear_arptables
# - sets policy to accept
# - flushes chains
# - removes custom chains
# ==============================
sub clear_arptables {
	$rc = `$tool -P INPUT ACCEPT`;
	unless($? == 0) { print "ERROR: $rc\n"; exit -1 };
	$rc = `$tool -P FORWARD ACCEPT`;
	unless($? == 0) { print "ERROR: $rc\n"; exit -1 };
	$rc = `$tool -P OUTPUT ACCEPT`;
	unless($? == 0) { print "ERROR: $rc\n"; exit -1 };

	$rc = `$tool -F`;
	unless($? == 0) { print "ERROR: $rc\n"; exit -1 };

	$rc = `$tool -L`;
	unless($? == 0) { print "ERROR: $rc\n"; exit -1 };
	
	foreach $line (split("\n",$rc)) {
		unless ($line =~ m/Chain\s(.*?)\s\(.*references\)/) { next; }
		$rc = `$tool -X $1`;
		unless($? == 0) { print "ERROR: $rc\n"; exit -1 };
	}
}
# ==============================


unless (-x $tool) { print "ERROR: $tool isn't executable\n"; exit -1; };
&clear_arptables();

$line = 0;
while(<>) {
    $line++;
    if(m/^#/) { next; };
    if(m/^$/) { next; };

    if(m/^\*(.*)/) {
        $table = $1;
        next;
    }

    # Process a chain directive
    if(m/^\:(.*?)\s(.*)/) {
	# is it a user or a built in chain ?
	if ("$2" eq "-") { 
        	$rc = `$tool -t $table -N $1`;
	        unless($? == 0) {print "ERROR(line $line): $rc\n"; exit -1};
		next; 
	}
        $rc = `$tool -t $table -P $1 $2`;
        unless($? == 0) {print "ERROR(line $line): $rc\n"; exit -1};
        next;
    }
    $rc = `$tool -t $table $_`;
    unless($? == 0) {print "ERROR(line $line): $rc\n"; exit -1};
}
