Fix incrementation of qemu mac address

Fix #501

gns3server/modules/qemu/qemu_vm.py

@@ -40,6 +40,8 @@ from ..base_vm import BaseVM
 from ...schemas.qemu import QEMU_OBJECT_SCHEMA, QEMU_PLATFORMS
 from ...utils.asyncio import monitor_process
 from ...utils.images import md5sum
+from ...utils import macaddress_to_int, int_to_macaddress
+
 
 import logging
 log = logging.getLogger(__name__)
@@ -1374,7 +1376,7 @@ class QemuVM(BaseVM):
                 patched_qemu = True
 
         for adapter_number, adapter in enumerate(self._ethernet_adapters):
-            mac = "%s%02x" % (self._mac_address[:-2], (int(self._mac_address[-2:]) + adapter_number) % 255)
+            mac = int_to_macaddress(macaddress_to_int(self._mac_address) + adapter_number)
             nio = adapter.get_nio(0)
             if self._legacy_networking:
                 # legacy QEMU networking syntax (-net)

gns3server/utils/__init__.py

@@ -16,6 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import textwrap
 import posixpath
 
 
@@ -26,3 +27,20 @@ def force_unix_path(path):
 
     path = path.replace("\\", "/")
     return posixpath.normpath(path)
+
+
+def macaddress_to_int(macaddress):
+    """
+    Convert a macaddress with the format 00:0c:29:11:b0:0a to a int
+
+    :param macaddress: The mac address
+    :returns: Integer
+    """
+    return int(macaddress.replace(":", ""), 16)
+
+
+def int_to_macaddress(integer):
+    """
+    Convert an integer to a macaddress
+    """
+    return ":".join(textwrap.wrap("%012x" % (integer), width=2))