wpaspy: Add native Python implementation of ctrl_iface access

This can be used as a replacement for the wpaspy.c module that uses
wpa_ctrl.c to access wpa_supplicant/hostapd control interface. Only
the UNIX domain socket version of the control interface is currently
supported.

Signed-hostap: Jouni Malinen <j@w1.fi>

wpaspy/wpaspy.py

@@ -0,0 +1,70 @@
+#!/usr/bin/python
+#
+# wpa_supplicant/hostapd control interface using Python
+# Copyright (c) 2013, Jouni Malinen <j@w1.fi>
+#
+# This software may be distributed under the terms of the BSD license.
+# See README for more details.
+
+import os
+import socket
+import select
+
+counter = 0
+
+class Ctrl:
+    def __init__(self, path):
+        global counter
+        self.started = False
+        self.attached = False
+        self.s = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+        self.dest = path
+        self.local = "/tmp/wpa_ctrl_" + str(os.getpid()) + '-' + str(counter)
+        counter += 1
+        self.s.bind(self.local)
+        self.s.connect(self.dest)
+        self.started = True
+
+    def __del__(self):
+        self.close()
+
+    def close(self):
+        if self.attached:
+            self.detach()
+        if self.started:
+            self.s.close()
+            os.unlink(self.local)
+            self.started = False
+
+    def request(self, cmd):
+        self.s.send(cmd)
+        [r, w, e] = select.select([self.s], [], [], 10)
+        if r:
+            return self.s.recv(4096)
+        raise Exception("Timeout on waiting response")
+
+    def attach(self):
+        if self.attached:
+            return None
+        res = self.request("ATTACH")
+        if "OK" in res:
+            return None
+        raise Exception("ATTACH failed")
+
+    def detach(self):
+        if not self.attached:
+            return None
+        res = self.request("DETACH")
+        if "OK" in res:
+            return None
+        raise Exception("DETACH failed")
+
+    def pending(self):
+        [r, w, e] = select.select([self.s], [], [], 0)
+        if r:
+            return True
+        return False
+
+    def recv(self):
+        res = self.s.recv(4096)
+        return res