Change Link/TCLink to accept universal parameters

This also enables us to specify IP addresses for both sides
of a TCLink, which enables LinuxRouter to work with TCLink.

fixes #854
fixes #634

mininet/link.py

@@ -407,7 +407,7 @@ class Link( object ):
     def __init__( self, node1, node2, port1=None, port2=None,
                   intfName1=None, intfName2=None, addr1=None, addr2=None,
                   intf=Intf, cls1=None, cls2=None, params1=None,
-                  params2=None, fast=True ):
+                  params2=None, fast=True, **params ):
         """Create veth link to another node, making two new interfaces.
            node1: first node
            node2: second node
@@ -417,18 +417,15 @@ class Link( object ):
            cls1, cls2: optional interface-specific constructors
            intfName1: node1 interface name (optional)
            intfName2: node2  interface name (optional)
-           params1: parameters for interface 1
-           params2: parameters for interface 2"""
+           params1: parameters for interface 1 (optional)
+           params2: parameters for interface 2 (optional)
+           **params: additional parameters for both interfaces"""
+
         # This is a bit awkward; it seems that having everything in
         # params is more orthogonal, but being able to specify
         # in-line arguments is more convenient! So we support both.
-        if params1 is None:
-            params1 = {}
-        if params2 is None:
-            params2 = {}
-        # Allow passing in params1=params2
-        if params2 is params1:
-            params2 = dict( params1 )
+        params1 = dict( params1 ) if params1 else {}
+        params2 = dict( params2 ) if params2 else {}
         if port1 is not None:
             params1[ 'port' ] = port1
         if port2 is not None:
@@ -442,6 +439,10 @@ class Link( object ):
         if not intfName2:
             intfName2 = self.intfName( node2, params2[ 'port' ] )
 
+        # Update with remaining parameter list
+        params1.update( params )
+        params2.update( params )
+
         self.fast = fast
         if fast:
             params1.setdefault( 'moveIntfFn', self._ignore )
@@ -463,6 +464,7 @@ class Link( object ):
 
         # All we are is dust in the wind, and our two interfaces
         self.intf1, self.intf2 = intf1, intf2
+
     # pylint: enable=too-many-branches
 
     @staticmethod
@@ -548,17 +550,11 @@ class OVSLink( Link ):
 
 
 class TCLink( Link ):
-    "Link with symmetric TC interfaces configured via opts"
-    def __init__( self, node1, node2, port1=None, port2=None,
-                  intfName1=None, intfName2=None,
-                  addr1=None, addr2=None, **params ):
-        Link.__init__( self, node1, node2, port1=port1, port2=port2,
-                       intfName1=intfName1, intfName2=intfName2,
-                       cls1=TCIntf,
-                       cls2=TCIntf,
-                       addr1=addr1, addr2=addr2,
-                       params1=params,
-                       params2=params )
+    "Link with TC interfaces"
+    def __init__( self, *args, **kwargs):
+        kwargs.setdefault( 'cls1', TCIntf )
+        kwargs.setdefault( 'cls2', TCIntf )
+        Link.__init__( self, *args, **kwargs)
 
 
 class TCULink( TCLink ):