unbound/pythonmod/examples/resmod.py

   1 '''
   2  resmod.py: This example shows how to modify the response from iterator
   3
   4  Copyright (c) 2009, Zdenek Vasicek (vasicek AT fit.vutbr.cz)
   5                      Marek Vavrusa  (xvavru00 AT stud.fit.vutbr.cz)
   6
   7  This software is open source.
   8
   9  Redistribution and use in source and binary forms, with or without
  10  modification, are permitted provided that the following conditions
  11  are met:
  12
  13     * Redistributions of source code must retain the above copyright notice,
  14       this list of conditions and the following disclaimer.
  15
  16     * Redistributions in binary form must reproduce the above copyright notice,
  17       this list of conditions and the following disclaimer in the documentation
  18       and/or other materials provided with the distribution.
  19
  20     * Neither the name of the organization nor the names of its
  21       contributors may be used to endorse or promote products derived from this
  22       software without specific prior written permission.
  23
  24  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  26  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  27  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
  28  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  POSSIBILITY OF SUCH DAMAGE.
  35 '''
  36
  37 def init(id, cfg): return True
  38
  39 def deinit(id): return True
  40
  41 def inform_super(id, qstate, superqstate, qdata): return True
  42
  43 def setTTL(qstate, ttl):
  44     """Updates return_msg TTL and the TTL of all the RRs"""
  45     if qstate.return_msg:
  46         qstate.return_msg.rep.ttl = ttl
  47         if (qstate.return_msg.rep):
  48             for i in range(0,qstate.return_msg.rep.rrset_count):
  49                 d = qstate.return_msg.rep.rrsets[i].entry.data
  50                 for j in range(0,d.count+d.rrsig_count):
  51                     d.rr_ttl[j] = ttl
  52
  53 def operate(id, event, qstate, qdata):
  54     if (event == MODULE_EVENT_NEW) or (event == MODULE_EVENT_PASS):
  55         #pass the query to validator
  56         qstate.ext_state[id] = MODULE_WAIT_MODULE
  57         return True
  58
  59     if event == MODULE_EVENT_MODDONE:
  60         log_info("pythonmod: iterator module done")
  61
  62         if not qstate.return_msg:
  63             qstate.ext_state[id] = MODULE_FINISHED
  64             return True
  65
  66         #modify the response
  67
  68         qdn = qstate.qinfo.qname_str
  69         if qdn.endswith(".nic.cz."):
  70             #invalidate response in cache added by iterator
  71             #invalidateQueryInCache(qstate, qstate.return_msg.qinfo)
  72
  73             #modify TTL to 10 secs and store response in cache
  74             #setTTL(qstate, 5)
  75             #if not storeQueryInCache(qstate, qstate.return_msg.qinfo, qstate.return_msg.rep, 0):
  76             #    qstate.ext_state[id] = MODULE_ERROR
  77             #    return False
  78
  79             #modify TTL of response, which will be send to a) validator and then b) client
  80             setTTL(qstate, 10)
  81             qstate.return_rcode = RCODE_NOERROR
  82
  83         qstate.ext_state[id] = MODULE_FINISHED
  84         return True
  85
  86     log_err("pythonmod: bad event")
  87     qstate.ext_state[id] = MODULE_ERROR
  88     return True