selftests: tc-testing: cleanup on Ctrl-C

Cleanup net namespaces and other resources if we get a SIGINT (Ctrl-C).
As user visible resources are allocated on a per test basis, it's only
required to catch this condition when (possibly) running tests.

So far calling post_suite is enough to free up anything that might
linger.

A missing keyword replacement for nsPlugin is also included.

Signed-off-by: Pedro Tammela <[e-mail]>
Acked-by: Jamal Hadi Salim <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/selftests/tc-testing/plugin-lib/nsPlugin.py

···
             print('{}.post_suite'.format(self.sub_class))
 
         # Make sure we don't leak resources
-        cmd = "$IP -a netns del"
+        cmd = self._replace_keywords("$IP -a netns del")
 
         if self.args.verbose > 3:
             print('_exec_cmd:  command "{}"'.format(cmd))

tools/testing/selftests/tc-testing/tdc.py

···
     if args.verbose > 2:
         print('args is {}'.format(args))
 
-    set_operation_mode(pm, parser, args, remaining)
+    try:
+        set_operation_mode(pm, parser, args, remaining)
+    except KeyboardInterrupt:
+        # Cleanup on Ctrl-C
+        pm.call_post_suite(None)
 
 if __name__ == "__main__":
     main()