Add test for BSN shell command extension
diff --git a/tests/bsn_shell.py b/tests/bsn_shell.py
new file mode 100644
index 0000000..f4d9969
--- /dev/null
+++ b/tests/bsn_shell.py
@@ -0,0 +1,47 @@
+"""
+"""
+import struct
+
+import logging
+
+from oftest import config
+import oftest.controller as controller
+import oftest.cstruct as ofp
+import oftest.message as message
+import oftest.base_tests as base_tests
+
+from oftest.testutils import *
+
+@nonstandard
+class BSNShellCommand(base_tests.SimpleDataPlane):
+    """
+    Exercise BSN vendor extension for running a shell command on the switch
+    """
+
+    def bsn_shell_command(self, cmd):
+        """
+        Use the BSN_SHELL_COMMAND vendor command to run the given command
+        and receive the output
+        """
+        m = message.vendor()
+        m.vendor = 0x005c16c7
+        m.data = struct.pack("!LL", 6, 0) + cmd
+        rc = self.controller.message_send(m)
+        self.assertNotEqual(rc, -1, "Error sending shell command")
+        out = ""
+        while True:
+            m, r = self.controller.poll(ofp.OFPT_VENDOR, 60)
+            self.assertEqual(m.vendor, 0x005c16c7, "Wrong vendor ID")
+            subtype = struct.unpack("!L", m.data[:4])[0]
+            if subtype == 7:
+               out += m.data[4:]
+            elif subtype == 8:
+               status = struct.unpack("!LL", m.data)[1]
+               return status, out
+            else:
+               assert False, "Wrong subtype"
+
+    def runTest(self):
+        status, out = self.bsn_shell_command("echo _one     space_")
+        self.assertEqual(status, 0, "Shell command returned %s != 0" % status)
+        self.assertEqual(out, "_one space_\n", "Shell command output: '%r'" % out)