use hex value for short session ID used in naming interfaces

use interface names "vethOOOOO.ii.ss" and "vethOOOOO.iipss" for veth pairs

(where OOOOO = object id, ii = interface index, ss = hex short session ID)

fixes bug #260 virtual interface names too long
(Boeing r1894)

daemon/core/netns/vnode.py

@@ -167,9 +167,9 @@ class SimpleLxcNode(PyCoreNode):
             if ifname is None:
                 ifname = "eth%d" % ifindex
             sessionid = self.session.shortsessionid()
-            name = "veth%s.%s.1.%s" % (self.objid, ifindex, sessionid)
+            name = "veth%s.%sp%s" % (self.objid, ifindex, sessionid)
             localname = "veth%s.%s.%s" % (self.objid, ifindex, sessionid)
-            if len(ifname) > 16:
+            if len(localname) >= 16:
                 raise ValueError, "interface local name '%s' to long" % \
                         localname
             ifclass = VEth

daemon/core/session.py

@@ -689,7 +689,8 @@ class Session(object):
         ''' Return a shorter version of the session ID, appropriate for
             interface names, where length may be limited.
         '''
-        return (self.sessionid >> 8) ^ (self.sessionid & ((1 << 8) - 1))
+        ssid = (self.sessionid >> 8) ^ (self.sessionid & ((1 << 8) - 1))
+        return "%x" % ssid
 
     def sendnodeemuid(self, handler, nodenum):
         ''' Send back node messages to the GUI for node messages that had

gui/util.tcl

@@ -1160,7 +1160,8 @@ proc get_term_prog { want_default } {
 
 # short session ID used by Python daemon for interface names
 proc shortSessionID { sid } {
-    return [ expr { ($sid >> 8) ^ ($sid & ((1<<8) - 1)) } ]
+    set ssid [ expr { ($sid >> 8) ^ ($sid & ((1<<8) - 1)) } ]
+    return [format "%x" $ssid]
 }