small changes in tun/tap interface creation

src/netns/interface.py

@@ -235,7 +235,7 @@ class TapNodeInterface(NSInterface):
         self._fd = None
         self._slave = None
         iface = netns.iproute.interface(name = self._gen_if_name())
-        iface, self._fd = netns.iproute.create_tap(iface, use_pi)
+        iface, self._fd = netns.iproute.create_tap(iface, use_pi = use_pi)
         netns.iproute.change_netns(iface.name, node.pid)
         super(TapNodeInterface, self).__init__(node, iface.index)
 
@@ -256,13 +256,14 @@ class TunNodeInterface(NSInterface):
     """Class to create a tun interface inside a name space, it
     can be connected to a Switch object with emulation of link
     characteristics."""
-    def __init__(self, node):
+    def __init__(self, node, use_pi = False):
         """Create a new tap interface. 'node' is the name space in which this
         interface should be put."""
         self._fd = None
         self._slave = None
         iface = netns.iproute.interface(name = self._gen_if_name())
-        iface, self._fd = netns.iproute.create_tun(iface)
+        iface, self._fd = netns.iproute.create_tap(iface, use_pi = use_pi,
+                tun = True)
         netns.iproute.change_netns(iface.name, node.pid)
         super(TunNodeInterface, self).__init__(node, iface.index)
 

src/netns/iproute.py

@@ -901,15 +901,19 @@ def set_tc(iface, bandwidth = None, delay = None, delay_jitter = None,
     for c in commands:
         execute(c)
 
-def create_tap(iface, use_pi = False):
-    """Creates a tap device and returns the associated file descriptor"""
+def create_tap(iface, use_pi = False, tun = False):
+    """Creates a tap/tun device and returns the associated file descriptor"""
     if isinstance(iface, str):
         iface = interface(name = iface)
     assert iface.name
 
+    IFF_TUN     = 0x0001
     IFF_TAP     = 0x0002
     IFF_NO_PI   = 0x1000
     TUNSETIFF   = 0x400454ca
+    if tun:
+        mode = IFF_TUN
+    else:
         mode = IFF_TAP
     if not use_pi:
         mode |= IFF_NO_PI
@@ -929,28 +933,3 @@ def create_tap(iface, use_pi = False):
     interfaces = get_if_data()[1]
     return interfaces[iface.name], fd
 
-def create_tun(iface):
-    """Creates a tun device and returns the associated file descriptor"""
-    if isinstance(iface, str):
-        iface = interface(name = iface)
-    assert iface.name
-
-    IFF_TUN     = 0x0001
-    TUNSETIFF   = 0x400454ca
-    mode = IFF_TUN
-
-    fd = os.open("/dev/net/tun", os.O_RDWR)
-
-    err = fcntl.ioctl(fd, TUNSETIFF, struct.pack("16sH", iface.name, mode))
-    if err < 0:
-        os.close(fd)
-        raise RuntimeError("Could not configure device %s" % iface.name)
-
-    try:
-        set_if(iface)
-    except:
-        os.close(fd)
-        raise
-    interfaces = get_if_data()[1]
-    return interfaces[iface.name], fd
-

src/netns/node.py

@@ -116,8 +116,8 @@ class Node(object):
             setattr(i, k, v)
         return i
 
-    def add_tun(self, **kwargs):
-        i = netns.interface.TunNodeInterface(self)
+    def add_tun(self, use_pi = False, **kwargs):
+        i = netns.interface.TunNodeInterface(self, use_pi)
         for k, v in kwargs.items():
             setattr(i, k, v)
         return i