--- bin/dhcpd.pl	2009/07/28 10:29:33	17
+++ bin/dhcpd.pl	2009/07/28 16:35:49	22
@@ -5,6 +5,8 @@
 use strict;
 use warnings;
 
+use autodie;
+
 use IO::Socket::INET;
 use Net::DHCP::Packet;
 use Net::DHCP::Constants;
@@ -15,10 +17,18 @@
 
 my $debug = shift @ARGV;
 
-our ( $file, $next_file );
+our ( $file, $gpxe_file );
 our ( $ip_from, $ip_to ) = ( 10, 100 );
 
-our $server_ip = readlink 'conf/server.ip';
+our $server_ip = readlink 'conf/server.ip' if -l 'conf/server.ip';
+
+if ( ! $server_ip ) {
+	$server_ip = `/sbin/ifconfig`;
+	$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
+	warn "auto-configure server ip to $server_ip\n";
+} else {
+	warn "server ip $server_ip\n";
+}
 
 my $sock = IO::Socket::INET->new(
 	LocalPort	=> 67,
@@ -41,8 +51,8 @@
 	my $conf = "conf/$server_ip";
 	mkdir $conf unless -e $conf;
 
-	if ( -e "$conf/$mac" ) {
-		my $ip = read_file "conf/mac/$mac";
+	if ( -e "$conf/mac/$mac" ) {
+		my $ip = read_file "$conf/mac/$mac";
 		print "$mac old $ip\n";
 		return $ip;
 	}
@@ -58,7 +68,8 @@
 	}
 
 	write_file "$conf/mac/$mac", $ip;
-	symlink    "$conf/mac/$mac", "conf/ip/$ip";
+	unlink     "$conf/ip/$ip" if -e "$conf/ip/$ip";
+	symlink    "$conf/mac/$mac", "$conf/ip/$ip";
 
 	print "$mac NEW $ip\n";
 
@@ -88,13 +99,12 @@
 
 		my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
 		my $ip = client_ip($mac);
+		my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
 
-		if ( ! $file ) {
-			if ( $dhcp->getOptionValue(DHO_USER_CLASS()) ne 'gPXE' ) {
-				$file = 'undionly.kpxe';
-			} else {
-				$file = $next_file;
-			}
+		if ( $user_class eq 'gPXE' ) {
+			$file = $gpxe_file;
+		} elsif ( ! $file ) {
+			$file = 'undionly.kpxe';
 		}
 
 		my $packet = new Net::DHCP::Packet(
@@ -112,8 +122,8 @@
         	DHO_SUBNET_MASK() => '255.0.0.0',
 		);
 
-		warn ">> $mac == $ip server $server_ip\n";
-		
+		warn ">> $mac == $ip server: $server_ip file: $file\n";
+
 		warn "## ",$packet->toString(),"\n" if $debug;
 
 		my $reply = IO::Socket::INET->new(