fix(KVM): unique MAC in all network cards

issue #1294

lib/Ravada.pm

@@ -2489,6 +2489,7 @@ sub _execute {
     die "I can't fork" if !defined $pid;
 
     if ( $pid == 0 ) {
+        srand();
         $self->_do_execute_command($sub, $request);
         exit;
     }

lib/Ravada/Domain/KVM.pm

@@ -1963,7 +1963,7 @@ sub _set_controller_network($self, $number, $data) {
     my $pci_slot = $self->_new_pci_slot();
 
     my $device = "<interface type='network'>
-        <mac address='52:54:00:a7:49:71'/>
+        <mac address='".$self->_vm->_new_mac()."'/>
         <source network='default'/>
         <model type='$driver'/>
         <address type='pci' domain='0x0000' bus='0x00' slot='$pci_slot' function='0x0'/>

lib/Ravada/VM/KVM.pm

@@ -64,6 +64,7 @@ $DIR_XML = "/var/lib/ravada/xml/" if $0 =~ m{^/usr/sbin};
 our $FILE_CONFIG_QEMU = "/etc/libvirt/qemu.conf";
 
 our $XML = XML::LibXML->new();
+our %USED_MAC;
 
 #-----------
 #
@@ -2041,52 +2042,55 @@ sub _new_uuid {
 
 }
 
-sub _xml_modify_mac {
-    my $self = shift;
-    my $doc = shift or confess "Missing XML doc";
-    my @old_macs;
-
+sub _read_used_macs($self) {
+    return if keys %USED_MAC;
     for my $dom ($self->vm->list_all_domains) {
         my $doc;
         eval { $doc = $XML->load_xml(string => $dom->get_xml_description()) } ;
         next if !$doc;
 
         for my $nic ( $doc->findnodes('/domain/devices/interface/mac')) {
-            my $nic_mac = $nic->getAttribute('address');
-            push @old_macs,($nic_mac);
+            my $nic_mac = lc($nic->getAttribute('address'));
+            $USED_MAC{$nic_mac}++;
         }
     }
+}
 
-    for my $if_mac ($doc->findnodes('/domain/devices/interface/mac') ) {
-        my $mac = $if_mac->getAttribute('address');
-
-        my @macparts0 = split/:/,$mac;
+sub _new_mac($self,$mac='52:54:00:a7:49:71') {
 
-        my $new_mac;
+    $self->_read_used_macs();
+    my @macparts = split/:/,$mac;
+    $macparts[5] = sprintf"%02X",($$ % 254);
 
     my @tried;
     my $foundit;
     for ( 1 .. 1000 ) {
-            for my $cont ( 1 .. 1000 ) {
-                my @macparts = @macparts0;
             my $pos = int(rand(scalar(@macparts)-3))+3;
+            for ( 0 .. 2 ) {
                 my $num =sprintf "%02X", rand(0xff);
                 die "Missing num " if !defined $num;
                 $macparts[$pos] = $num;
-                $new_mac = lc(join(":",@macparts));
+                $pos++;
+                $pos = 3 if $pos>5;
+            }
+            my $new_mac = lc(join(":",@macparts));
             push @tried,($new_mac);
 
-                last if !grep /^$new_mac$/i,@old_macs && $self->_unique_mac($new_mac);
-                push @old_macs,($new_mac);
+            return $new_mac if !$USED_MAC{$new_mac}++ && $self->_unique_mac($new_mac);
     }
+    die "I can't find a new unique mac\n".Dumper(\@tried) if !$foundit;
 
-            if ( $self->_unique_mac($new_mac) ) {
+}
+
+sub _xml_modify_mac {
+    my $self = shift;
+    my $doc = shift or confess "Missing XML doc";
+
+    for my $if_mac ($doc->findnodes('/domain/devices/interface/mac') ) {
+        my $mac = $if_mac->getAttribute('address');
+
+        my $new_mac = $self->_new_mac($mac);;
         $if_mac->setAttribute(address => $new_mac);
-                $foundit = 1;
-                last;
-            }
-        }
-        die "I can't find a new unique mac '$new_mac'\n".Dumper(\@tried) if !$foundit;
     }
 }