unbound/pythonmod/examples/calc.py

   1 # -*- coding: utf-8 -*-
   2 '''
   3  calc.py: DNS-based calculator
   4
   5  Copyright (c) 2009, Zdenek Vasicek (vasicek AT fit.vutbr.cz)
   6                      Marek Vavrusa  (xvavru00 AT stud.fit.vutbr.cz)
   7
   8  This software is open source.
   9
  10  Redistribution and use in source and binary forms, with or without
  11  modification, are permitted provided that the following conditions
  12  are met:
  13
  14     * Redistributions of source code must retain the above copyright notice,
  15       this list of conditions and the following disclaimer.
  16
  17     * Redistributions in binary form must reproduce the above copyright notice,
  18       this list of conditions and the following disclaimer in the documentation
  19       and/or other materials provided with the distribution.
  20
  21     * Neither the name of the organization nor the names of its
  22       contributors may be used to endorse or promote products derived from this
  23       software without specific prior written permission.
  24
  25  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
  29  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  POSSIBILITY OF SUCH DAMAGE.
  36 '''
  37
  38 #Try: dig @localhost 1*25._calc_.cz.
  39
  40 def init(id, cfg): return True
  41 def deinit(id): return True
  42 def inform_super(id, qstate, superqstate, qdata): return True
  43
  44 def operate(id, event, qstate, qdata):
  45
  46     if (event == MODULE_EVENT_NEW) or (event == MODULE_EVENT_PASS):
  47
  48         if qstate.qinfo.qname_str.endswith("._calc_.cz."):
  49             try:
  50                 res = eval(''.join(qstate.qinfo.qname_list[0:-3]))
  51             except:
  52                 res = "exception"
  53
  54             msg = DNSMessage(qstate.qinfo.qname_str, RR_TYPE_TXT, RR_CLASS_IN, PKT_QR | PKT_RA | PKT_AA) #, 300)
  55             msg.answer.append("%s 300 IN TXT \"%s\"" % (qstate.qinfo.qname_str,res))
  56             if not msg.set_return_msg(qstate):
  57                qstate.ext_state[id] = MODULE_ERROR
  58                return True
  59
  60             qstate.return_rcode = RCODE_NOERROR
  61             qstate.ext_state[id] = MODULE_FINISHED
  62             return True
  63
  64         else:
  65             #Pass on the unknown query to the iterator
  66             qstate.ext_state[id] = MODULE_WAIT_MODULE
  67             return True
  68
  69     elif event == MODULE_EVENT_MODDONE:
  70         #the iterator has finished
  71         qstate.ext_state[id] = MODULE_FINISHED
  72         return True
  73
  74     log_err("pythonmod: Unknown event")
  75     qstate.ext_state[id] = MODULE_ERROR
  76     return True
  77